release: 0.114.1 (bug/notice-language)

The value sweep wrapped two plain t() values in raw(), so the delete-user and the YouTube subscribe
confirms read "[object Object]" where the email or the channel was. tsc cannot see that seam, so a
syntax contract now refuses a notice value handed to t() and an already-said text kept in a notice.
The raw() doc says what it is: text kept as fetched (a Plex title in the language it was fetched in).
seasonTitleText's no-number branches are tested.

CHANGELOG.md

@@ -7,6 +7,12 @@ edit the release notes and re-run the generator.
 
 Upgrading, pinning a version and rolling back: [docs/self-hosting.md](docs/self-hosting.md#upgrading).
 
+## 0.114.1 — 2026-10-30
+
+### Fixed
+
+- Notifications follow a language switch: a notice on screen and every row in the notification center are said again in the new language, their buttons too.
+
 ## 0.114.0 — 2026-10-29
 
 ### New

VERSION

@@ -1 +1 @@
-0.114.0
+0.114.1

backend/app/refusal.py

@@ -1,7 +1,7 @@
 """A request the app refuses, said in a way the UI can put in the reader's language.
 
 Every refusal the API answers carries a structured `detail` — `{code, reason, …params}` — and the client
-translates it (`lib/api/core.ts` `localizeDetail`). A bare English string reached the Hungarian UI
+translates it (`lib/api/refusalText.ts` `localizeDetail`). A bare English string reached the Hungarian UI
 verbatim: the blocking error dialog, and every inline surface that printed `HttpError.detail`, showed
 whatever sentence the route happened to hand-write. `refused` is the generic family
 (`errors.refused.<reason>`, the params interpolated into the sentence); the older specific codes

backend/app/routes/files.py

@@ -139,7 +139,7 @@ def own_job_for_update(db: Session, user: User, job_id: int) -> "DownloadJob":
 
 def quota_detail(e: quota.QuotaExceeded) -> dict:
     """Structured error the trilingual client localizes (reason key + numbers), instead of a
-    pre-baked English string with a dot-decimal GB value. See lib/api.ts localizeDetail()."""
+    pre-baked English string with a dot-decimal GB value. See lib/api/refusalText.ts localizeDetail()."""
     return {"code": "quota", "reason": e.reason, "limit": e.limit, "current": e.current}
 
 

backend/app/routes/saved_views.py

@@ -128,7 +128,8 @@ def update_view(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise refused(409, "view_name_taken", name=view.name) from None
+        # The name asked for: the rollback has put the view's old name back on `view`.
+        raise refused(409, "view_name_taken", name=name) from None
     return _serialize(view)
 
 

backend/app/routes/tags.py

@@ -107,7 +107,8 @@ def update_tag(
         db.commit()
     except IntegrityError:
         db.rollback()
-        raise refused(409, "tag_name_taken", name=tag.name) from None
+        # The name asked for: the rollback has put the tag's old name back on `tag`.
+        raise refused(409, "tag_name_taken", name=name) from None
     return {
         "ok": True,
         "id": tag.id,

backend/tests/test_name_taken_detail.py

@@ -0,0 +1,46 @@
+"""A rename onto a name already taken says WHICH name is taken: the one asked for, not the row's
+old name (the rollback that follows the conflict puts the old name back on the row). DB lane.
+"""
+
+from fastapi.testclient import TestClient
+
+import app.state as state
+from app.auth import current_user
+from app.db import get_db
+from app.main import app
+from app.models import User
+
+
+def _client(db, monkeypatch, override_dep):
+    u = User(email="taken@example.com")
+    db.add(u)
+    db.commit()
+    monkeypatch.setattr(
+        state, "_configured_cache", True
+    )  # the request gate 503s an unconfigured app
+    override_dep(get_db, db.info["request"])
+    override_dep(current_user, lambda: u)
+    return TestClient(app)
+
+
+def test_renaming_a_view_onto_a_taken_name_names_the_taken_one(db, monkeypatch, override_dep):
+    c = _client(db, monkeypatch, override_dep)
+    gaming = c.post("/api/saved-views", json={"name": "gaming", "filters": {}, "source": "feed"})
+    assert gaming.status_code == 200
+    hh = c.post("/api/saved-views", json={"name": "hh", "filters": {}, "source": "feed"}).json()
+
+    r = c.patch(f"/api/saved-views/{hh['id']}", json={"name": "gaming"})
+
+    assert r.status_code == 409
+    assert r.json()["detail"] == {"code": "refused", "reason": "view_name_taken", "name": "gaming"}
+
+
+def test_renaming_a_tag_onto_a_taken_name_names_the_taken_one(db, monkeypatch, override_dep):
+    c = _client(db, monkeypatch, override_dep)
+    assert c.post("/api/tags", json={"name": "music"}).status_code == 200
+    news = c.post("/api/tags", json={"name": "news"}).json()
+
+    r = c.patch(f"/api/tags/{news['id']}", json={"name": "music"})
+
+    assert r.status_code == 409
+    assert r.json()["detail"] == {"code": "refused", "reason": "tag_name_taken", "name": "music"}

frontend/e2e/bookmark.spec.ts

@@ -196,7 +196,7 @@ test.describe("a bookmark reopens the view it was taken of", () => {
   test("a channel page's own tab, over the page it was opened from", async ({ page, browser }) => {
     await openApp(page, "/?page=feed");
     await expect(page.getByTestId("video-card").first()).toBeVisible();
-    expect(await clickVisibleChannelLink(page)).toBe(true);
+    await clickVisibleChannelLink(page);
     const title = await page.getByTestId("channel-title").textContent();
     await tab(page, "About").click();
     const fresh = await bookmarked(browser, page);

frontend/e2e/channel.spec.ts

@@ -48,7 +48,7 @@ test.describe("channel view", () => {
     // `.first()` here would grab an overscan card ABOVE the viewport, and Playwright's scroll-into-
     // view would move the feed before navigating, so Back would restore that moved position, not
     // the one under test. (This is what made the test fail while the app was in fact correct.)
-    expect(await clickVisibleChannelLink(page)).toBe(true);
+    await clickVisibleChannelLink(page);
     await expect(page.getByTestId("channel-title")).toBeVisible();
     await page.getByTestId("channel-back").click();
     await expect(page.getByTestId("video-card").first()).toBeVisible();

frontend/e2e/helpers.ts

@@ -33,23 +33,41 @@ export async function gotoPage(page: Page, id: string): Promise<void> {
  * that then asserts on where the feed was. Being inside the viewport is not enough either: a card
  * can sit under the page chrome above the scroller (the update banner, the toolbar band), and the
  * covered click makes Playwright scroll and retry — the same move (webkit failed 3 in 24).
- * So the link must be the element hit at its own centre. Returns false if none found.
+ * So the link must be the element hit at its own centre; none within the wait fails the test, with
+ * the poll's own message. Looked for again until one is, not once: a fresh load is still settling
+ * when the first card shows (the links move down ~55px), and webkit can answer the hit test at a
+ * link's new centre with the card under it — every link missed in 1 of 30 runs. A link that goes
+ * away mid-look (its evaluate waits for it, or throws) counts as not hit, so the next look runs.
  */
-export async function clickVisibleChannelLink(page: Page): Promise<boolean> {
+export async function clickVisibleChannelLink(page: Page): Promise<void> {
   const links = page.getByTestId("video-card-channel").filter({ visible: true });
-  const count = await links.count();
-  for (let i = 0; i < count; i++) {
-    const hittable = await links.nth(i).evaluate((el) => {
-      const r = el.getBoundingClientRect();
-      const hit = document.elementFromPoint(r.left + r.width / 2, r.top + r.height / 2);
-      return hit !== null && el.contains(hit);
-    });
-    if (hittable) {
-      await links.nth(i).click();
-      return true;
+  let index = -1;
+  const findHittable = async () => {
+    const count = await links.count();
+    for (let i = 0; i < count; i++) {
+      const hittable = await links
+        .nth(i)
+        .evaluate(
+          (el) => {
+            const r = el.getBoundingClientRect();
+            const hit = document.elementFromPoint(r.left + r.width / 2, r.top + r.height / 2);
+            return hit !== null && el.contains(hit);
+          },
+          undefined,
+          { timeout: 1000 },
+        )
+        .catch(() => false);
+      if (hittable) return i;
     }
-  }
-  return false;
+    return -1;
+  };
+  await expect
+    .poll(async () => (index = await findHittable()), {
+      message: "a channel link hit at its own centre",
+      timeout: 5000,
+    })
+    .toBeGreaterThan(-1);
+  await links.nth(index).click();
 }
 
 /**

frontend/src/PlaylistEditFailures.dom.test.tsx

@@ -22,7 +22,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 vi.mock("./components/ui/confirmContext", () => ({ useConfirm: () => async () => true }));
 const { notify } = vi.hoisted(() => ({
-  notify: vi.fn((_n: { level: string; message: string }) => 0),
+  notify: vi.fn((_n: { level: string; message: NotifText }) => 0),
 }));
 vi.mock("./lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("./lib/notifications")>()),
@@ -35,6 +35,7 @@ import PlexPlaylistAdd from "./features/plexCards/PlexPlaylistAdd";
 import TagManager from "./features/channel/TagManager";
 import { api, HttpError, type PlexCard } from "./lib/api";
 import { qk } from "./lib/queryKeys";
+import type { NotifText } from "./lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -98,7 +99,7 @@ describe("the Plex playlist page", () => {
       () => fireEvent.contextMenu(screen.getByText("Movie 1").closest("[data-nav-index]")!),
       "plex.playlist.removeFromPlaylist",
     );
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await act(async () => void (await new Promise((r) => setTimeout(r, 20))));
     expect(screen.getByText("Movie 1")).toBeTruthy();
   });
@@ -119,7 +120,7 @@ describe("the Plex playlist page", () => {
     const field = await screen.findByDisplayValue("Films");
     fireEvent.change(field, { target: { value: "Movies" } });
     fireEvent.keyDown(field, { key: "Enter" });
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     expect(screen.getByDisplayValue("Movies")).toBeTruthy(); // still open to try again
   });
 
@@ -154,7 +155,7 @@ describe("the add-to-playlist popover", () => {
     );
     fireEvent.click(screen.getByLabelText("playlists.addToPlaylist"));
     fireEvent.click(await screen.findByRole("menuitemcheckbox", { hidden: true }));
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await waitFor(() => expect(lists.mock.calls.length).toBeGreaterThan(1));
   });
 
@@ -282,7 +283,7 @@ describe("the add-to-playlist popover", () => {
     fireEvent.click(await screen.findByText("Gone"));
     // The server's own localized reason wins over the caller's fallback when the detail is
     // STRUCTURED — same as the twin above. What is under test is that anything is said at all.
-    await waitFor(() => expect(errors()).toEqual(["gone playlist"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("playlist").detailData }]));
     await waitFor(() => expect(lists.mock.calls.length).toBeGreaterThan(1));
   });
 });
@@ -300,7 +301,7 @@ describe("the tag manager", () => {
       </QueryClientProvider>,
     );
     fireEvent.click(await screen.findByLabelText("tagManager.delete"));
-    await waitFor(() => expect(errors()).toEqual(["gone tag"]));
+    await waitFor(() => expect(errors()).toEqual([{ detail: gone("tag").detailData }]));
     await waitFor(() => expect(tags.mock.calls.length).toBeGreaterThan(1));
   });
 });

frontend/src/WriteFailureReporting.dom.test.tsx

@@ -19,7 +19,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 vi.mock("./components/ui/confirmContext", () => ({ useConfirm: () => async () => true }));
 const { notify } = vi.hoisted(() => ({
-  notify: vi.fn((_n: { level: string; title?: string; message: string }) => 0),
+  notify: vi.fn((_n: { level: string; title?: NotifText; message: NotifText }) => 0),
 }));
 vi.mock("./lib/notifications", async (importOriginal) => ({
   ...(await importOriginal<typeof import("./lib/notifications")>()),
@@ -30,6 +30,7 @@ import PlexCollectionEditor from "./modules/plex/PlexCollectionEditor";
 import UploadDialog from "./modules/files/UploadDialog";
 import DownloadDialog from "./features/downloads/DownloadDialog";
 import { api, HttpError } from "./lib/api";
+import { msg, type NotifText } from "./lib/notifications";
 
 beforeAll(() => {
   class Stub {
@@ -87,7 +88,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("Marathon"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.editFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.editFailed")]));
   });
 
   it("says so when enabling editing is refused", async () => {
@@ -97,7 +98,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("plex.collEditor.makeEditable"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.editFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.editFailed")]));
   });
 
   it("says so when a CONFIRMED delete does not happen", async () => {
@@ -108,7 +109,7 @@ describe("the Plex collection editor", () => {
     );
     mount();
     fireEvent.click(await screen.findByText("plex.collEditor.delete"));
-    await waitFor(() => expect(errors()).toEqual(["plex.collection.deleteFailed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("plex.collection.deleteFailed")]));
   });
 });
 
@@ -144,7 +145,7 @@ describe("the upload dialog", () => {
     mount();
     pick();
     fireEvent.click(screen.getByText("downloads.upload.submit"));
-    await waitFor(() => expect(errors()).toEqual(["downloads.upload.failed"]));
+    await waitFor(() => expect(errors()).toEqual([msg("downloads.upload.failed")]));
   });
 
   it("says nothing when the user cancelled it themselves", async () => {
@@ -172,6 +173,6 @@ describe("the download dialog", () => {
     );
     await screen.findByText("Best");
     fireEvent.click(screen.getByText("downloads.dialog.submit"));
-    await waitFor(() => expect(errors()).toEqual(["errors.writeFailed.enqueueDownload"]));
+    await waitFor(() => expect(errors()).toEqual([msg("errors.writeFailed.enqueueDownload")]));
   });
 });

frontend/src/components/ui/Modal.dom.test.tsx

@@ -21,7 +21,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 vi.mock("../../lib/history", () => ({ useBackToClose: () => {} }));
 
 import Modal from "./Modal";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { pushLayer, removeLayer, useLayer } from "../../lib/layerStack";
 import { createPortal, flushSync } from "react-dom";
 
@@ -121,7 +121,7 @@ describe("Modal focus trap (offsetParent stubbed 'visible')", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "info", message: "Saved" }));
+    act(() => void notify({ level: "info", message: raw("Saved") }));
     try {
       const dismissToast = screen.getByTitle("notifications.dismiss");
       // The panel's last control is no longer the trap's edge: Tab carries on (natively) to the toast.
@@ -234,7 +234,7 @@ describe("Modal focus trap (offsetParent stubbed 'visible')", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "error", message: "Nope" }));
+    act(() => void notify({ level: "error", message: raw("Nope") }));
     const dismissToast = screen.getByTitle("notifications.dismiss");
     dismissToast.focus();
     expect(document.activeElement).toBe(dismissToast); // the scenario is actually being driven
@@ -455,7 +455,7 @@ describe("Modal — toasts raised while it is open", () => {
         <Body />
       </Modal>,
     );
-    act(() => void notify({ level: "error", message: "Couldn't share it." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't share it.") }));
     expect(screen.getByRole("dialog").textContent).toContain("Couldn't share it.");
   });
 });

frontend/src/components/ui/Toaster.dom.test.tsx

@@ -14,7 +14,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 });
 
 import Toaster from "./Toaster";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { dockUnderToasts } from "../../lib/toastDock";
 
 afterEach(() => {
@@ -31,7 +31,7 @@ describe("Toaster — one host shows the toasts", () => {
         <Toaster />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "Couldn't remove the video." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't remove the video.") }));
     expect(screen.getByTestId("app").textContent).toContain("Couldn't remove the video.");
 
     const overlay = render(
@@ -54,7 +54,7 @@ describe("Toaster — one host shows the toasts", () => {
   it("lets a click through where there is no toast and nothing docked, and not where there is", () => {
     const Docked = () => <button>dock</button>;
     const stop = dockUnderToasts(Docked);
-    notify({ level: "info", message: "hello" });
+    notify({ level: "info", message: raw("hello") });
     render(<Toaster />);
     const region = document.querySelector<HTMLElement>("[data-toast-region]")!;
     // The empty part of the region (beside and above a docked control) must not swallow the page's
@@ -75,7 +75,7 @@ describe("Toaster — one host shows the toasts", () => {
         <Toaster overlay />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     fireEvent.click(screen.getByText("boom"));
     expect(backdrop).not.toHaveBeenCalled();
   });
@@ -86,11 +86,11 @@ describe("Toaster — handing the toasts to another host", () => {
     // The new host gets them as NEW nodes: a screen reader read every one out again, an error
     // assertively, each time a player (or any dialog) opened or closed.
     render(<Toaster />);
-    act(() => void notify({ level: "error", message: "old news" }));
+    act(() => void notify({ level: "error", message: raw("old news") }));
     render(<Toaster overlay />);
     const old = screen.getByText("old news").closest(".toast-card")!;
     expect(old.getAttribute("role")).toBeNull();
-    act(() => void notify({ level: "error", message: "fresh" }));
+    act(() => void notify({ level: "error", message: raw("fresh") }));
     expect(screen.getByText("fresh").closest(".toast-card")!.getAttribute("role")).toBe("alert");
   });
 
@@ -99,8 +99,8 @@ describe("Toaster — handing the toasts to another host", () => {
     // host last showed — re-read on every render, this host's own "first" turned silent the moment
     // "second" arrived (its own screen had become the handover by then).
     render(<Toaster />);
-    act(() => void notify({ level: "error", message: "first" }));
-    act(() => void notify({ level: "error", message: "second" }));
+    act(() => void notify({ level: "error", message: raw("first") }));
+    act(() => void notify({ level: "error", message: raw("second") }));
     const card = (text: string) => screen.getByText(text).closest(".toast-card")!;
     expect(card("first").getAttribute("role")).toBe("alert");
     expect(card("second").getAttribute("role")).toBe("alert");
@@ -111,7 +111,7 @@ describe("Toaster — handing the toasts to another host", () => {
     // inserted announces them anyway. React flushes effects in the SAME task as that render, so the
     // arming has to wait for the next one — a screen reader reads the region's state after the task.
     render(<Toaster />);
-    act(() => void notify({ level: "info", message: "saved" }));
+    act(() => void notify({ level: "info", message: raw("saved") }));
     const overlay = render(<Toaster overlay />);
     const region = overlay.container.querySelector("[aria-live]")!;
     expect(region.textContent).toContain("saved"); // it took the toast over…
@@ -135,7 +135,7 @@ describe("Toaster — handing the toasts to another host", () => {
               <Toaster overlay />
               <button
                 onClick={() => {
-                  notify({ level: "success", message: "upload queued" });
+                  notify({ level: "success", message: raw("upload queued") });
                   setOpen(false);
                 }}
               >
@@ -147,7 +147,7 @@ describe("Toaster — handing the toasts to another host", () => {
       );
     }
     render(<Stage />);
-    act(() => void notify({ level: "error", message: "old news" }));
+    act(() => void notify({ level: "error", message: raw("old news") }));
     fireEvent.click(screen.getByText("upload"));
 
     const card = (text: string) => screen.getByText(text).closest(".toast-card")!;
@@ -168,7 +168,7 @@ describe("Toaster — handing the toasts to another host", () => {
         <Toaster overlay order={2} />
       </div>,
     );
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     expect(screen.getByTestId("dialog").textContent).toContain("boom");
     // The player swaps its host (leaving true fullscreen) while the dialog stays open.
     player.rerender(
@@ -188,7 +188,7 @@ describe("Toaster — handing the toasts to another host", () => {
     const t0 = Date.now();
     const now = vi.spyOn(Date, "now").mockReturnValue(t0);
     render(<Toaster />);
-    act(() => void notify({ level: "info", message: "saved" }));
+    act(() => void notify({ level: "info", message: raw("saved") }));
     now.mockReturnValue(t0 + 4000);
     render(<Toaster overlay />);
     const bar = screen.getByText("saved").closest(".toast-card")!.lastElementChild as HTMLElement;
@@ -199,7 +199,7 @@ describe("Toaster — handing the toasts to another host", () => {
     // At the app's own spot (bottom-4) the stack sat on the Plex transport row and PlayerModal's
     // docked bar, above them at z-overlay, and took their clicks for as long as a toast was up.
     render(<Toaster overlay />);
-    act(() => void notify({ level: "error", message: "boom" }));
+    act(() => void notify({ level: "error", message: raw("boom") }));
     const host = hosts()[0]!.closest("[data-toast-region]")!;
     expect(host.className).toContain("bottom-24");
     expect(host.className).toContain("pointer-events-none");
@@ -218,9 +218,9 @@ describe("Toaster — a toast's actions", () => {
       () =>
         void notify({
           level: "success",
-          message: "Downloaded",
-          action: { label: "Copy link", onClick: copy },
-          secondaryAction: { label: "Open", onClick: open },
+          message: raw("Downloaded"),
+          action: { label: raw("Copy link"), onClick: copy },
+          secondaryAction: { label: raw("Open"), onClick: open },
         }),
     );
     expect(screen.getByRole("button", { name: "Copy link" })).toBeTruthy();

frontend/src/components/ui/Toaster.language.dom.test.tsx

@@ -0,0 +1,104 @@
+// @vitest-environment jsdom
+//
+// A notice is said in the reader's language when it is shown, not in the one it was raised in. The
+// text used to be translated by the caller and kept so: after a language switch every toast and every
+// row of the notification center stayed in the old language, and so did the history after a reload.
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { act, cleanup, render, screen } from "@testing-library/react";
+import i18n from "../../i18n";
+import Toaster from "./Toaster";
+import { clearAll, msg, notify, raw, sayNotif } from "../../lib/notifications";
+
+beforeEach(async () => {
+  await i18n.changeLanguage("en");
+});
+afterEach(async () => {
+  cleanup();
+  act(() => clearAll());
+  await i18n.changeLanguage("en");
+});
+
+describe("a notice speaks the reader's language of the moment", () => {
+  it("a toast raised in English reads Hungarian after the switch", async () => {
+    render(<Toaster />);
+    act(() => void notify({ level: "success", message: msg("common.copy.done") }));
+    const en = i18n.getFixedT("en")("common.copy.done");
+    const hu = i18n.getFixedT("hu")("common.copy.done");
+    expect(en).not.toBe(hu);
+    expect(screen.getByText(en)).toBeTruthy();
+
+    await act(async () => void (await i18n.changeLanguage("hu")));
+    expect(screen.getByText(hu)).toBeTruthy();
+    expect(screen.queryByText(en)).toBeNull();
+  });
+
+  it("its button is said again too, beside the text it acts on", async () => {
+    render(<Toaster />);
+    act(
+      () =>
+        void notify({
+          message: msg("common.copy.done"),
+          action: { label: msg("common.undo"), onClick: () => {} },
+        }),
+    );
+    expect(screen.getByRole("button", { name: "Undo" })).toBeTruthy();
+
+    await act(async () => void (await i18n.changeLanguage("hu")));
+    expect(screen.getByRole("button", { name: "Visszavonás" })).toBeTruthy();
+    expect(screen.queryByRole("button", { name: "Undo" })).toBeNull();
+  });
+
+  it("a server refusal is said again in the language of the moment", async () => {
+    render(<Toaster />);
+    act(
+      () =>
+        void notify({
+          level: "error",
+          message: { detail: { code: "not_found", reason: "view" } },
+        }),
+    );
+    expect(screen.getByText("This view doesn't exist any more")).toBeTruthy();
+
+    await act(async () => void (await i18n.changeLanguage("hu")));
+    expect(screen.getByText("Ez a nézet már nem létezik")).toBeTruthy();
+  });
+
+  it("a value inside the text is said again too, and a number is grouped the reader's way", async () => {
+    const text = msg("settings.takeout.read", {
+      name: raw("watch-history.json"),
+      count: 12345,
+      n: { number: 12345 },
+    });
+    const en = sayNotif(text);
+    await i18n.changeLanguage("hu");
+    const hu = sayNotif(text);
+    expect(en).toContain("12,345");
+    expect(hu).not.toContain("12,345");
+    expect(hu).toContain("watch-history.json");
+    expect(hu).not.toBe(en);
+  });
+});
+
+describe("the history kept from before", () => {
+  beforeEach(() => {
+    localStorage.clear();
+    vi.resetModules();
+  });
+
+  it("shows a notice stored as text as it was stored", async () => {
+    localStorage.setItem("siftlode.owner", "5");
+    localStorage.setItem(
+      "siftlode.notifications",
+      JSON.stringify([
+        { id: 1, level: "info", title: "Old title", message: "Old text", ts: 1, read: true },
+      ]),
+    );
+    const notifications = await import("../../lib/notifications");
+    const { claimLocalData } = await import("../../lib/storage");
+    claimLocalData(5);
+    const n = notifications.getNotifications()[0]!;
+    expect(n.message).toEqual(raw("Old text"));
+    expect(n.title).toEqual(raw("Old title"));
+    expect(notifications.sayNotif(n.message)).toBe("Old text");
+  });
+});

frontend/src/components/ui/Toaster.strictmode.dom.test.tsx

@@ -23,7 +23,7 @@ vi.mock("react-i18next", async (importOriginal) => {
 
 import Toaster from "./Toaster";
 import { useOverlayOrder } from "./overlayOrder";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -37,7 +37,7 @@ function Harness() {
     <>
       <button
         onClick={() => {
-          notify({ level: "success", message: "Uploaded" });
+          notify({ level: "success", message: raw("Uploaded") });
           setOpen(false); // …in the SAME handler: one batch, one commit
         }}
       >

frontend/src/components/ui/Toaster.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useId, useLayoutEffect, useState, useSyncExternalStore } from "react";
 import { useTranslation } from "react-i18next";
 import { X } from "lucide-react";
-import { dismiss, getActiveToasts, subscribe } from "../../lib/notifications";
+import { dismiss, getActiveToasts, sayNotif, subscribe } from "../../lib/notifications";
 import { createStore } from "../../lib/store";
 import { useToastDock } from "../../lib/toastDock";
 import { useOverlayOrder } from "./overlayOrder";
@@ -162,9 +162,11 @@ export default function Toaster({
             >
               <Icon className={`w-5 h-5 shrink-0 mt-0.5 ${color}`} />
               <div className="min-w-0 flex-1">
-                {toast.title && <div className="text-sm font-semibold">{toast.title}</div>}
+                {toast.title && (
+                  <div className="text-sm font-semibold">{sayNotif(toast.title, t)}</div>
+                )}
                 <div className="text-sm wrap-break-word">
-                  {toast.message}
+                  {sayNotif(toast.message, t)}
                   {toast.repeat > 1 && (
                     <span className="ml-1.5 align-middle text-2xs font-semibold text-muted tabular-nums">
                       ×{toast.repeat}
@@ -174,10 +176,10 @@ export default function Toaster({
                 {(toast.action || toast.secondaryAction) && (
                   <div className="mt-1 flex flex-wrap gap-x-4">
                     {[toast.action, toast.secondaryAction].map(
-                      (action) =>
+                      (action, i) =>
                         action && (
                           <Button
-                            key={action.label}
+                            key={i}
                             variant="link"
                             onClick={() => {
                               action.onClick();
@@ -185,7 +187,7 @@ export default function Toaster({
                             }}
                             className="text-sm"
                           >
-                            {action.label}
+                            {sayNotif(action.label, t)}
                           </Button>
                         ),
                     )}

frontend/src/components/ui/copyItems.tsx

@@ -2,7 +2,7 @@ import { useTranslation } from "react-i18next";
 import { Copy, Link2 } from "lucide-react";
 
 import { copyText } from "../../lib/clipboard";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify } from "../../lib/notifications";
 import { type ActionMenuItem } from "./ActionMenu";
 
 // "Copy title" and "Copy link", the two rows every object's menu ends its middle group with
@@ -17,12 +17,12 @@ type Named = "title" | "name";
 
 export function useCopyItems() {
   const { t } = useTranslation();
-  const copy = (text: string, done: string) => {
+  const copy = (text: string, done: NotifText) => {
     void copyText(text).then((ok) =>
       notify(
         ok
           ? { level: "success", message: done }
-          : { level: "error", message: t("common.copy.failed") },
+          : { level: "error", message: msg("common.copy.failed") },
       ),
     );
   };
@@ -43,7 +43,7 @@ export function useCopyItems() {
             label: t(named === "title" ? "common.copy.title" : "common.copy.name"),
             icon: <Copy className="w-4 h-4" />,
             inGesture: true,
-            onSelect: () => copy(text, t("common.copy.done")),
+            onSelect: () => copy(text, msg("common.copy.done")),
           },
         ]
       : []),
@@ -54,7 +54,7 @@ export function useCopyItems() {
             label: linkLabel ?? t("common.copy.link"),
             icon: <Link2 className="w-4 h-4" />,
             inGesture: true,
-            onSelect: () => copy(link, t("common.copy.linkDone")),
+            onSelect: () => copy(link, msg("common.copy.linkDone")),
           },
         ]
       : []),

frontend/src/components/ui/uiI18n.contract.test.ts

@@ -19,8 +19,9 @@ const PLATFORM_NAMESPACES = new Set([
 ]);
 
 const files = readSources(__dirname, "./**/*.{ts,tsx}");
-// `t("ns.…")` and `t(\`ns.…\`)` — the namespace is everything before the first dot.
-const KEY = /\bt\(\s*["`]([A-Za-z]+)\./g;
+// `t("ns.…")` and `t(\`ns.…\`)`, and a notice's `msg("ns.…")` (the same key, said when shown) — the
+// namespace is everything before the first dot.
+const KEY = /\b(?:t|msg)\(\s*["`]([A-Za-z]+)\./g;
 
 describe("components/ui/ speaks only platform i18n namespaces", () => {
   it("names no feature namespace", () => {
@@ -37,5 +38,6 @@ describe("components/ui/ speaks only platform i18n namespaces", () => {
 
   it("sees a feature namespace when one is used", () => {
     expect([...'t("plex.loading")'.matchAll(KEY)].map((m) => m[1])).toEqual(["plex"]);
+    expect([...'msg("plex.loading")'.matchAll(KEY)].map((m) => m[1])).toEqual(["plex"]);
   });
 });

frontend/src/components/ui/useCopyFeedback.dom.test.ts

@@ -11,8 +11,12 @@ vi.mock("react-i18next", async (importOriginal) => ({
   useTranslation: () => ({ i18n: { language: "en" }, t: (key: string) => key }),
 }));
 vi.mock("../../lib/clipboard", () => ({ copyText: h.copyText }));
-vi.mock("../../lib/notifications", () => ({ notify: h.notify }));
+vi.mock("../../lib/notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../../lib/notifications")>()),
+  notify: h.notify,
+}));
 
+import { msg } from "../../lib/notifications";
 import { useCopyFeedback } from "./useCopyFeedback";
 
 afterEach(() => {
@@ -27,7 +31,7 @@ describe("useCopyFeedback", () => {
     await act(() => result.current.copy("sfl_x"));
     expect(h.copyText).toHaveBeenCalledWith("sfl_x");
     expect(result.current.copied).toBe(true);
-    expect(h.notify).toHaveBeenCalledWith({ level: "success", message: "common.copy.done" });
+    expect(h.notify).toHaveBeenCalledWith({ level: "success", message: msg("common.copy.done") });
     act(() => void vi.advanceTimersByTime(2000));
     expect(result.current.copied).toBe(false);
   });
@@ -49,6 +53,6 @@ describe("useCopyFeedback", () => {
     const { result } = renderHook(() => useCopyFeedback());
     await act(() => result.current.copy("sfl_x"));
     expect(result.current.copied).toBe(false);
-    expect(h.notify).toHaveBeenCalledWith({ level: "warning", message: "common.copy.failed" });
+    expect(h.notify).toHaveBeenCalledWith({ level: "warning", message: msg("common.copy.failed") });
   });
 });

frontend/src/components/ui/useCopyFeedback.ts

@@ -1,8 +1,7 @@
 import { useEffect, useRef, useState } from "react";
-import { useTranslation } from "react-i18next";
 
 import { copyText } from "../../lib/clipboard";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 
 // How long a Copy button reads "Copied" after it worked.
 const COPIED_MS = 2000;
@@ -15,7 +14,6 @@ const COPIED_MS = 2000;
  *
  *  A feature file, not `ui/`: it speaks the app's notifications (as `copyItems` does). */
 export function useCopyFeedback(): { copied: boolean; copy: (value: string) => Promise<void> } {
-  const { t } = useTranslation();
   const [copied, setCopied] = useState(false);
   // One reset at a time: a copy again within the moment starts it over, not cut short by the last.
   const timer = useRef<number | undefined>(undefined);
@@ -23,12 +21,12 @@ export function useCopyFeedback(): { copied: boolean; copy: (value: string) => P
   const copy = async (value: string) => {
     if (await copyText(value)) {
       setCopied(true);
-      notify({ level: "success", message: t("common.copy.done") });
+      notify({ level: "success", message: msg("common.copy.done") });
       window.clearTimeout(timer.current);
       timer.current = window.setTimeout(() => setCopied(false), COPIED_MS);
       return;
     }
-    notify({ level: "warning", message: t("common.copy.failed") });
+    notify({ level: "warning", message: msg("common.copy.failed") });
   };
   return { copied, copy };
 }

frontend/src/content/release-notes/en.json

@@ -1,4 +1,12 @@
 [
+  {
+    "version": "0.114.1",
+    "date": "2026-10-30",
+    "new": [],
+    "fixed": [
+      "Notifications follow a language switch: a notice on screen and every row in the notification center are said again in the new language, their buttons too."
+    ]
+  },
   {
     "version": "0.114.0",
     "date": "2026-10-29",

frontend/src/content/release-notes/hu.json

@@ -1,4 +1,12 @@
 [
+  {
+    "version": "0.114.1",
+    "date": "2026-10-30",
+    "new": [],
+    "fixed": [
+      "Az értesítések követik a nyelvváltást: a képernyőn lévő értesítés és az értesítési központ minden sora az új nyelven szól, a gombjaik is."
+    ]
+  },
   {
     "version": "0.114.0",
     "date": "2026-10-29",

frontend/src/features/channel/TagManager.tsx

@@ -4,7 +4,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { qk } from "../../lib/queryKeys";
 import { Plus, Trash2 } from "lucide-react";
 import { api, type Tag } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify, raw } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { useScrollFade } from "../../lib/useScrollFade";
 import { Button } from "../../components/ui/Button";
@@ -137,22 +137,22 @@ export default function TagManager({
   });
   // A failure is said and the list refetched — a tag deleted in another tab used to fail in silence
   // (a 404 `not_found/tag` gets no global dialog) and stay listed.
-  const onFailed = (e: unknown, fallback: string) => {
+  const onFailed = (e: unknown, fallback: NotifText) => {
     notifyActionError(e, fallback);
     invalidate();
   };
   const rename = useMutation({
     mutationFn: (v: { id: number; name: string }) => api.updateTag(v.id, { name: v.name }),
     onSuccess: invalidate,
-    onError: (e) => onFailed(e, t("tagManager.renameFailed")),
+    onError: (e) => onFailed(e, msg("tagManager.renameFailed")),
   });
   const del = useMutation({
     mutationFn: (v: { id: number; name: string }) => api.deleteTag(v.id),
     onSuccess: (_d, v) => {
       invalidate();
-      notify({ level: "success", message: t("tagManager.deleted", { name: v.name }) });
+      notify({ level: "success", message: msg("tagManager.deleted", { name: raw(v.name) }) });
     },
-    onError: (e) => onFailed(e, t("tagManager.deleteFailed")),
+    onError: (e) => onFailed(e, msg("tagManager.deleteFailed")),
   });
 
   // Picking a channel from a tag's popover: close the dialog, then focus it in the manager.

frontend/src/features/comfort/comfortPin.tsx

@@ -6,7 +6,7 @@ import { Loader2, Pin, PinOff } from "lucide-react";
 import { plexLang } from "../../i18n";
 import { api, type DiscoverCard, type PinKind } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
-import { notify } from "../../lib/notifications";
+import { msg, type NotifText, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 
@@ -81,9 +81,9 @@ export interface ComfortPin {
   /** `pinIdOf` and `toggle` stay module-local until a second consumer needs them: publishing them
    *  invites the next surface to re-derive the three-state loading dance (pinned / not pinned /
    *  not known yet) that `item` already encapsulates, which is what this file exists to prevent. */
-  remove: (pinId: number, title: string) => void;
+  remove: (pinId: number, title: NotifText) => void;
   /** The pin/unpin row, ready to spread into any `ActionMenuItem[]`. Empty for a null target. */
-  item: (target: PinTarget | null, title: string) => ActionMenuItem[];
+  item: (target: PinTarget | null, title: NotifText) => ActionMenuItem[];
 }
 
 /**
@@ -134,37 +134,37 @@ export function useComfortPin(open: boolean): ComfortPin {
   }, [qc]);
 
   const add = useCallback(
-    async (target: PinTarget, title: string) => {
+    async (target: PinTarget, title: NotifText) => {
       try {
         await api.addComfortPin(target.kind, target.ref);
         // The shelf lives on another page, so without this the click has no visible consequence at
         // all from the feed — the one place a toast genuinely carries the whole feedback.
-        notify({ level: "success", message: t("home.pin.added", { title }) });
+        notify({ level: "success", message: msg("home.pin.added", { title }) });
       } catch (e) {
-        notifyActionError(e, t("home.pin.addFailed"));
+        notifyActionError(e, msg("home.pin.addFailed"));
       }
       invalidate();
     },
-    [invalidate, t],
+    [invalidate],
   );
 
   const remove = useCallback(
-    (pinId: number, title: string) => {
+    (pinId: number, title: NotifText) => {
       void (async () => {
         try {
           await api.removeComfortPin(pinId);
-          notify({ level: "success", message: t("home.pin.removed", { title }) });
+          notify({ level: "success", message: msg("home.pin.removed", { title }) });
         } catch (e) {
-          notifyActionError(e, t("home.pin.removeFailed"));
+          notifyActionError(e, msg("home.pin.removeFailed"));
         }
         invalidate();
       })();
     },
-    [invalidate, t],
+    [invalidate],
   );
 
   const toggle = useCallback(
-    (target: PinTarget, title: string) => {
+    (target: PinTarget, title: NotifText) => {
       const pinId = pinIdOf(target);
       if (pinId == null) void add(target, title);
       else remove(pinId, title);
@@ -173,7 +173,7 @@ export function useComfortPin(open: boolean): ComfortPin {
   );
 
   const item = useCallback(
-    (target: PinTarget | null, title: string): ActionMenuItem[] => {
+    (target: PinTarget | null, title: NotifText): ActionMenuItem[] => {
       if (!target) return [];
       const pinId = pinIdOf(target);
       // Still loading: an honest "we don't know yet" row rather than a confident "Pin" over

frontend/src/features/diagnostics/DebugRecorder.tsx

@@ -18,7 +18,7 @@ import {
 } from "../../lib/debugRecorder";
 import { formatDateTimeSec, formatDuration } from "../../lib/format";
 import { useLayer } from "../../lib/layerStack";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { dockUnderToasts } from "../../lib/toastDock";
 import { useMe } from "../../lib/useMe";
@@ -73,7 +73,7 @@ export default function DebugRecorder() {
     if (!id || !until) return;
     const wait = Math.min(Date.parse(until) - Date.now(), 2 ** 31 - 1);
     const timer = window.setTimeout(() => {
-      notify({ level: "warning", message: t("recorder.pill.expired", { count: minutes ?? 0 }) });
+      notify({ level: "warning", message: msg("recorder.pill.expired", { count: minutes ?? 0 }) });
       openComposer(id);
       void qc.invalidateQueries({ queryKey: qk.me() });
     }, wait);

frontend/src/features/diagnostics/IssueComposer.tsx

@@ -6,7 +6,7 @@ import { ExternalLink, FileText, Plus, Server, X } from "lucide-react";
 import { api, type DebugScreenshot, type DebugSession, type ServerLogRow } from "../../lib/api";
 import { closeComposer } from "../../lib/debugRecorder";
 import { formatBytes, formatDateTimeSec, formatUnit } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { useMe } from "../../lib/useMe";
 import {
   draftSteps,
@@ -217,7 +217,7 @@ function ComposerBody({
     meta: { failTitle: "recorder.composer.sendFailed" },
     onSuccess: (r) => {
       qc.setQueryData(qk.debugSession(session.id), r.session);
-      notify({ level: "success", message: t("recorder.composer.sentOk") });
+      notify({ level: "success", message: msg("recorder.composer.sentOk") });
     },
     // A failure half-way still created the issue: show what the server now has.
     onSettled: async () => {

frontend/src/features/diagnostics/useDebugRecording.ts

@@ -1,6 +1,5 @@
 import { useCallback } from "react";
 import { useIsMutating, useMutation, useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 
 import { api, type DebugSession, type DebugSessionLevel } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
@@ -14,7 +13,7 @@ import {
 } from "../../lib/debugRecorder";
 import { flushNow, liveSession } from "../../lib/diagnostics";
 import { log } from "../../lib/log";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { updateMeCache, useMe } from "../../lib/useMe";
 
@@ -22,7 +21,6 @@ import { updateMeCache, useMe } from "../../lib/useMe";
  *  Diagnosztika and the command palette. The session itself is `me.debug_session` — the server's
  *  answer, so a reload, another tab or the cap all show the same thing. */
 export function useDebugRecording() {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const me = useMe();
   const session = liveSession(me?.debug_session);
@@ -54,7 +52,7 @@ export function useDebugRecording() {
     meta: { failTitle: "recorder.pill.stopFailed" },
     onSuccess: (r) => {
       setSession(null);
-      notify({ level: "success", message: t("recorder.pill.stopped") });
+      notify({ level: "success", message: msg("recorder.pill.stopped") });
       openComposer(r.session.id);
     },
   });
@@ -78,7 +76,7 @@ export function useDebugRecording() {
       );
       // In the evidence too, where the step list is drafted from: which step it belongs to.
       log.info("debug.screenshot", "screenshot taken", { screenshot: r.screenshot.id });
-      notify({ level: "success", message: t("recorder.pill.shotSaved") });
+      notify({ level: "success", message: msg("recorder.pill.shotSaved") });
     },
   });
 
@@ -95,9 +93,9 @@ export function useDebugRecording() {
       const n = nextStep(sessionId);
       const text = label.trim();
       log.info("debug.step", text || `step ${n}`, { n, ...(text ? { label: text } : {}) });
-      notify({ level: "info", message: t("recorder.pill.stepMarked", { n }) });
+      notify({ level: "info", message: msg("recorder.pill.stepMarked", { n }) });
     },
-    [sessionId, t],
+    [sessionId],
   );
 
   /** Capture this tab and attach it. `hide` runs around the capture so the pill is not in the
@@ -111,7 +109,7 @@ export function useDebugRecording() {
       await new Promise((r) => requestAnimationFrame(() => requestAnimationFrame(r)));
       image = await captureTab();
     } catch (err) {
-      notifyActionError(err, t("recorder.pill.shotFailed"));
+      notifyActionError(err, msg("recorder.pill.shotFailed"));
     }
     hide(false);
     if (image) shoot.mutate({ id: session.id, image });

frontend/src/features/downloads/DownloadDialog.tsx

@@ -9,7 +9,7 @@ import { invalidateDownloads } from "../../lib/downloads";
 
 // Lazy: the full profile editor only opens from the dialog's "manage presets" affordance.
 const ProfileEditor = lazy(() => import("../../modules/settings/ProfileEditor"));
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { showInTray } from "../../lib/downloadQueue";
 import { profileName } from "../../lib/vocab";
@@ -63,15 +63,15 @@ export default function DownloadDialog({
       setLastProfile(chosen);
       notify({
         level: "success",
-        message: t("downloads.dialog.added"),
-        action: { label: t("downloads.dialog.view"), onClick: () => showInTray(job.id) },
+        message: msg("downloads.dialog.added"),
+        action: { label: msg("downloads.dialog.view"), onClick: () => showInTray(job.id) },
       });
       onClose();
     } catch (e) {
       // A quota or validation refusal (422/409) is already in the global error dialog, which the
       // reporter skips; a 403/404/429 or a lost connection is not, and used to leave the dialog
       // open with nothing said.
-      notifyActionError(e, t("errors.writeFailed.enqueueDownload"));
+      notifyActionError(e, msg("errors.writeFailed.enqueueDownload"));
       setBusy(false);
     }
   };

frontend/src/features/downloads/DownloadTray.dom.test.tsx

@@ -70,6 +70,7 @@ vi.mock("../../lib/notifications", async (importOriginal) => ({
 }));
 
 import DownloadTray from "./DownloadTray";
+import { msg, type NotifText, raw } from "../../lib/notifications";
 import { noteQueue, resetQueueWatch, showInTray } from "../../lib/downloadQueue";
 import { pushLayer, removeLayer } from "../../lib/layerStack";
 import { qk } from "../../lib/queryKeys";
@@ -199,14 +200,15 @@ describe("DownloadTray", () => {
     poll([job(1, "done")], view);
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
     const notice = h.notify.mock.calls[0]![0] as {
-      title: string;
-      message: string;
-      action: { label: string; onClick: () => void };
-      secondaryAction: { label: string; onClick: () => void };
+      title: NotifText;
+      message: NotifText;
+      action: { label: NotifText; onClick: () => void };
+      secondaryAction: { label: NotifText; onClick: () => void };
     };
-    expect(notice.title).toBe("tray.done.title:Clip 1");
-    expect(notice.message).toBe("tray.done.phone");
-    expect(notice.action.label).toBe("tray.done.copyLink");
+    expect(notice.title).toEqual(msg("tray.done.title", { title: raw("Clip 1") }));
+    expect(notice.message).toEqual(msg("tray.done.phone"));
+    expect(notice.action.label).toEqual(msg("tray.done.copyLink"));
+    expect(notice.secondaryAction.label).toEqual(msg("tray.done.open"));
     notice.action.onClick();
     expect(h.share).toHaveBeenCalled();
     notice.secondaryAction.onClick();
@@ -225,9 +227,9 @@ describe("DownloadTray", () => {
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
     poll([job(1, "done"), job(2, "done")], view);
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(2));
-    expect(h.notify.mock.calls.map((c) => (c[0] as { title: string }).title)).toEqual([
-      "tray.done.title:Clip 1",
-      "tray.done.title:Clip 2",
+    expect(h.notify.mock.calls.map((c) => (c[0] as { title: NotifText }).title)).toEqual([
+      msg("tray.done.title", { title: raw("Clip 1") }),
+      msg("tray.done.title", { title: raw("Clip 2") }),
     ]);
   });
 
@@ -236,7 +238,9 @@ describe("DownloadTray", () => {
     const view = mount();
     poll([job(1, "done", { asset: { media_kind: "file" } as never })], view);
     await waitFor(() =>
-      expect(h.notify).toHaveBeenCalledWith(expect.objectContaining({ message: "tray.done.file" })),
+      expect(h.notify).toHaveBeenCalledWith(
+        expect.objectContaining({ message: msg("tray.done.file") }),
+      ),
     );
   });
 
@@ -257,7 +261,9 @@ describe("DownloadTray", () => {
     poll([job(1, "done", { source_key: "upload" })], view);
     await waitFor(() =>
       expect(h.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ title: "tray.done.uploadedTitle:Clip 1" }),
+        expect.objectContaining({
+          title: msg("tray.done.uploadedTitle", { title: raw("Clip 1") }),
+        }),
       ),
     );
   });

frontend/src/features/downloads/DownloadTray.tsx

@@ -30,7 +30,7 @@ import {
 } from "../../lib/downloadQueue";
 import { anyBlockingLayer } from "../../lib/layerStack";
 import { focusNavItem, navItemAttrs } from "../../lib/listNav";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { LS } from "../../lib/storage";
 import { useLiveQuery } from "../../lib/useLiveQuery";
@@ -191,16 +191,16 @@ export default function DownloadTray() {
     notify({
       level: "success",
       // An upload the worker had to convert first is done here too — it was never downloaded.
-      title: t(job.source_key === "upload" ? "tray.done.uploadedTitle" : "tray.done.title", {
-        title,
+      title: msg(job.source_key === "upload" ? "tray.done.uploadedTitle" : "tray.done.title", {
+        title: raw(title),
       }),
-      message: t(job.asset?.media_kind === "file" ? "tray.done.file" : "tray.done.phone"),
+      message: msg(job.asset?.media_kind === "file" ? "tray.done.file" : "tray.done.phone"),
       action: {
-        label: t("tray.done.copyLink"),
-        onClick: () => void quickShareLink(qc, { kind: "file", id: job.id }, t),
+        label: msg("tray.done.copyLink"),
+        onClick: () => void quickShareLink(qc, { kind: "file", id: job.id }),
       },
       secondaryAction: {
-        label: t("tray.done.open"),
+        label: msg("tray.done.open"),
         onClick: () => openFile(job.id, job.folder_id),
       },
     });
@@ -298,7 +298,7 @@ export default function DownloadTray() {
         id: "copyLink",
         label: t("tray.done.copyLink"),
         icon: <Link className="w-4 h-4" />,
-        onSelect: () => void quickShareLink(qc, { kind: "file", id: job.id }, t),
+        onSelect: () => void quickShareLink(qc, { kind: "file", id: job.id }),
       },
     ]);
   const menuItems = menu.target

frontend/src/features/downloads/useDownloadActions.tsx

@@ -9,6 +9,7 @@ import { useCopyItems } from "../../components/ui/copyItems";
 import { jobTitle } from "./downloadTitle";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 import { menuGroups } from "../../components/ui/menuGroups";
+import { msg } from "../../lib/notifications";
 
 // A queued download's ONE action list: the row's "…", its right-click, long-press and Shift+F10. The
 // row keeps its primary action (pause / resume / retry) and its state (the error and its details) in
@@ -56,7 +57,7 @@ export function useDownloadActions() {
           ? api.resumeDownload(id)
           : api.cancelDownload(id),
     onSuccess: () => invalidateDownloads(qc),
-    onError: (e, v) => notifyActionError(e, t(`errors.writeFailed.job.${v.op}`)),
+    onError: (e, v) => notifyActionError(e, msg(`errors.writeFailed.job.${v.op}`)),
   });
 
   const confirmThen = async (title: string, body: string, action: string, fn: () => void) => {

frontend/src/features/filters/useSavedViewsStore.ts

@@ -8,6 +8,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { ownKey } from "../../lib/storage";
 import { useConfirm } from "../../components/ui/confirmContext";
 import type { SavedViewsContext, ViewSource } from "./savedViewsContext";
+import { msg, type NotifText } from "../../lib/notifications";
 
 // Saved "smart views" serve two modules — the feed and Plex — and each owns one store of them in its
 // own folder, built on this hook. The two never switch into each other: a visit to Plex leaves the
@@ -114,7 +115,7 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
   const isDirty = displayView != null && activeView == null;
 
   const refresh = () => void qc.invalidateQueries({ queryKey: qk.savedViews(source) });
-  async function runViewMutation(fn: () => Promise<unknown>, failMsg: string): Promise<boolean> {
+  async function runViewMutation(fn: () => Promise<unknown>, failMsg: NotifText): Promise<boolean> {
     let ok = true;
     try {
       await fn();
@@ -146,28 +147,28 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
       if (!clean) return false;
       return runViewMutation(
         () => api.createView(clean, cfg.stripForSave(cfg.filters), source),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       );
     },
     rename: async (id, name) => {
       const next = name.trim();
       if (!next) return false;
-      return runViewMutation(() => api.updateView(id, { name: next }), t("views.actionFailed"));
+      return runViewMutation(() => api.updateView(id, { name: next }), msg("views.actionFailed"));
     },
     updateFilters: (id, filters) =>
-      runViewMutation(() => api.updateView(id, { filters }), t("views.actionFailed")),
+      runViewMutation(() => api.updateView(id, { filters }), msg("views.actionFailed")),
     saveCurrent: async (id) => {
       const filters = cfg.stripForSave(cfg.filters);
       const ok = await runViewMutation(
         () => api.updateView(id, { filters }),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       );
       return ok ? filters : null;
     },
     toggleDefault: (v) =>
       runViewMutation(
         () => api.updateView(v.id, { is_default: !v.is_default }),
-        t("views.actionFailed"),
+        msg("views.actionFailed"),
       ).then(() => undefined),
     remove: async (v) => {
       const ok = await confirm({
@@ -177,14 +178,14 @@ export function useSavedViewsStore(cfg: SavedViewsConfig): SavedViewsContext {
       });
       if (!ok) return false;
       if (stickyId === v.id) setStickyId(null);
-      return runViewMutation(() => api.deleteView(v.id), t("views.actionFailed"));
+      return runViewMutation(() => api.deleteView(v.id), msg("views.actionFailed"));
     },
     reorder: async (nextIds) => {
       qc.setQueryData<SavedView[]>(
         qk.savedViews(source),
         nextIds.map((id) => views.find((v) => v.id === id)!).filter(Boolean),
       );
-      await runViewMutation(() => api.reorderViews(nextIds), t("views.reorderFailed"));
+      await runViewMutation(() => api.reorderViews(nextIds), msg("views.reorderFailed"));
     },
   };
 }

frontend/src/features/player/ClipPanel.dom.test.tsx

@@ -30,10 +30,11 @@ vi.mock("../../lib/downloadQueue", () => ({ showInTray: (id: number) => showInTr
 const notifyActionError = vi.fn();
 vi.mock("../../lib/actionErrors", async (importOriginal) => {
   const actual = await importOriginal<typeof import("../../lib/actionErrors")>();
-  return { ...actual, notifyActionError: (e: unknown, t: string) => notifyActionError(e, t) };
+  return { ...actual, notifyActionError: (e: unknown, t: NotifText) => notifyActionError(e, t) };
 });
 
 import ClipPanel, { type ClipCrop, type ClipSource } from "./ClipPanel";
+import { msg, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -188,7 +189,7 @@ describe("ClipPanel", () => {
       display_name: "The bit",
     });
     expect(notify).toHaveBeenCalledWith(
-      expect.objectContaining({ level: "success", message: "clip.queued" }),
+      expect.objectContaining({ level: "success", message: msg("clip.queued") }),
     );
     // Its View opens the tray on the new clip.
     (
@@ -214,7 +215,7 @@ describe("ClipPanel", () => {
     fireEvent.click(screen.getByRole("button", { name: "clip.cut" }));
     await waitFor(() => expect(notifyActionError).toHaveBeenCalledTimes(1));
     expect(notifyActionError.mock.calls[0]![0]).toBe(err);
-    expect(notifyActionError.mock.calls[0]![1]).toBe("clip.failed");
+    expect(notifyActionError.mock.calls[0]![1]).toEqual(msg("clip.failed"));
     expect(onClose).not.toHaveBeenCalled();
     expect((screen.getByRole("button", { name: "clip.cut" }) as HTMLButtonElement).disabled).toBe(
       false,

frontend/src/features/player/ClipPanel.tsx

@@ -5,7 +5,7 @@ import { Crop, Crosshair, Maximize, Minus, Plus, Repeat, Scissors, X } from "luc
 import { api, type ClipRequest } from "../../lib/api";
 import { DISPLAY_NAME_MAX } from "../../lib/api/downloads";
 import { invalidateDownloads } from "../../lib/downloads";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { showInTray } from "../../lib/downloadQueue";
 import { log } from "../../lib/log";
@@ -197,14 +197,14 @@ export default function ClipPanel({
       log.info("clip.queued", "clip queued", { source: src.source, seconds: Math.round(length) });
       notify({
         level: "success",
-        message: t("clip.queued"),
-        action: { label: t("clip.view"), onClick: () => showInTray(job.id) },
+        message: msg("clip.queued"),
+        action: { label: msg("clip.view"), onClick: () => showInTray(job.id) },
       });
       onClose();
     } catch (err) {
       // A refusal the server explains (too long, quota) is already in the error dialog; a lost
       // connection or a 404 is not, and must not leave the panel looking as if nothing happened.
-      notifyActionError(err, t("clip.failed"));
+      notifyActionError(err, msg("clip.failed"));
       setBusy(false);
     }
   };

frontend/src/features/player/LinkedPlayer.tsx

@@ -1,5 +1,4 @@
 import { lazy, Suspense, useState } from "react";
-import { useTranslation } from "react-i18next";
 import { useQueryClient } from "@tanstack/react-query";
 import { type Video, type VideoStatus } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
@@ -7,6 +6,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { useStableCallback } from "../../lib/useLatest";
 import { writeVideoState } from "../video/videoWrites";
 import { useOpenLinkedPlayer } from "./useOpenLinkedPlayer";
+import { msg } from "../../lib/notifications";
 
 const PlayerModal = lazy(() => import("./PlayerModal"));
 
@@ -14,7 +14,6 @@ const PlayerModal = lazy(() => import("./PlayerModal"));
  *  channel manager, where the watched-videos dialog played it; any page a link names): the video
  *  alone. Decided at boot, once — `hosted` is whether the page on screen then opens it itself. */
 export function LinkedPlayer({ hosted }: { hosted: boolean }) {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const [own] = useState(!hosted);
   const [video, setVideo] = useState<Video | null>(null);
@@ -27,7 +26,7 @@ export function LinkedPlayer({ hosted }: { hosted: boolean }) {
     const write = writeVideoState(qc, id, status);
     write
       .then(() => qc.invalidateQueries({ queryKey: qk.feed() }))
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.videoState")));
     return write;
   });
   const close = useStableCallback(() => setVideo(null));

frontend/src/features/player/PlayerModal.dom.test.tsx

@@ -40,7 +40,7 @@ import { closeKeyboardHelp, toggleKeyboardHelp } from "../../lib/keymap";
 import { ConfirmProvider } from "../../components/ui/ConfirmProvider";
 import { useConfirm } from "../../components/ui/confirmContext";
 import { api, type Me, type Video, type VideoStatus } from "../../lib/api";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { writeVideoState } from "../video/videoWrites";
 
@@ -314,7 +314,7 @@ describe("PlayerModal — toasts raised while it is open", () => {
         onState={() => Promise.resolve()}
       />,
     );
-    act(() => void notify({ level: "error", message: "Couldn't remove the video." }));
+    act(() => void notify({ level: "error", message: raw("Couldn't remove the video.") }));
     expect(screen.getByTestId("player-modal").textContent).toContain("Couldn't remove the video.");
   });
 
@@ -336,7 +336,7 @@ describe("PlayerModal — toasts raised while it is open", () => {
     Object.defineProperty(document, "fullscreenElement", { configurable: true, get: () => stage });
     try {
       act(() => void document.dispatchEvent(new Event("fullscreenchange")));
-      act(() => void notify({ level: "error", message: "Connection lost" }));
+      act(() => void notify({ level: "error", message: raw("Connection lost") }));
       await waitFor(() => expect(stage.textContent).toContain("Connection lost"));
     } finally {
       delete (document as { fullscreenElement?: unknown }).fullscreenElement;

frontend/src/features/player/RelatedVideos.tsx

@@ -26,6 +26,7 @@ import VideoCard from "../video/VideoCard";
 import { VideoMenu } from "../video/VideoMenu";
 import { announceVideoState } from "../video/stateNotice";
 import { writeVideoState, writeWatchLater } from "../video/videoWrites";
+import { msg } from "../../lib/notifications";
 
 /** Which list YouTube fills in — on the video's topic or with what trends in Hungary — is a mood,
  *  decided at the list, and the account keeps the last one (the owner's pick). */
@@ -100,7 +101,7 @@ export function RelatedVideos({
         announceVideoState(id, status, v, () => onState(id, "new"));
       })
       .catch((e: unknown) => {
-        notifyActionError(e, t("errors.writeFailed.videoState"));
+        notifyActionError(e, msg("errors.writeFailed.videoState"));
         settle(seq);
       });
   };
@@ -118,7 +119,7 @@ export function RelatedVideos({
       .catch((e: unknown) => {
         notifyActionError(
           e,
-          t(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
+          msg(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
         );
         settle(seq);
       });

frontend/src/features/player/useOpenLinkedPlayer.dom.test.tsx

@@ -26,6 +26,7 @@ import { useOpenLinkedPlayer } from "./useOpenLinkedPlayer";
 import { LinkedPlayer } from "./LinkedPlayer";
 import { api, type Video } from "../../lib/api";
 import { notifyActionError } from "../../lib/actionErrors";
+import { msg } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 
 const vid = (id: string) => ({ id, title: id }) as unknown as Video;
@@ -76,7 +77,7 @@ describe("useOpenLinkedPlayer", () => {
     const open = vi.fn();
     renderHook(() => useOpenLinkedPlayer(true, () => undefined, open), { wrapper });
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(gone, "player.linkedFailed"),
+      expect(notifyActionError).toHaveBeenCalledWith(gone, msg("player.linkedFailed")),
     );
     expect(open).not.toHaveBeenCalled();
     // Said once: the address no longer names it, so a reload or a copied link does not say it again.

frontend/src/features/player/useOpenLinkedPlayer.ts

@@ -1,11 +1,11 @@
 import { useEffect, useEffectEvent, useRef, useState } from "react";
-import { useTranslation } from "react-i18next";
 import { useQuery } from "@tanstack/react-query";
 import { api, type Video } from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
 import { linkedPlayer, PLAYER_KEYS } from "../../lib/playerUrlState";
 import { clearParams } from "../../lib/urlState";
 import { notifyActionError } from "../../lib/actionErrors";
+import { msg } from "../../lib/notifications";
 
 /** Opens the player an address names (a reload, a bookmark — lib/playerUrlState) on the page that
  *  hosts it, once: read as the host mounts, opened once its list is in (`ready`). From the list when the
@@ -22,7 +22,6 @@ export function useOpenLinkedPlayer(
   open: (video: Video, inList: boolean) => void,
   scope: string | number | null = null,
 ): void {
-  const { t } = useTranslation();
   const [linked] = useState(() => linkedPlayer()?.watch ?? null);
   const [linkedScope] = useState(scope);
   // Opened, said to be gone or given up, once. A ref for the effect (a StrictMode re-run of it must
@@ -40,7 +39,7 @@ export function useOpenLinkedPlayer(
   });
   const openIt = useEffectEvent(open);
   const failed = useEffectEvent((err: unknown) => {
-    notifyActionError(err, t("player.linkedFailed"));
+    notifyActionError(err, msg("player.linkedFailed"));
     clearParams(...PLAYER_KEYS);
   });
   useEffect(() => {

frontend/src/features/plexCards/PlexCollectionAdd.tsx

@@ -8,6 +8,7 @@ import { PopoverSurface } from "../../components/ui/AnchoredPopover";
 import { useAnchoredPopover } from "../../components/ui/anchoredPopoverHooks";
 import { MembershipMenu } from "../../components/ui/MembershipMenu";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // "Add to collection…" from a movie or show card's menu: a panel beside the card that ticks the title
 // into or out of its library's manual collections, and names a new one — created with this title in
@@ -67,7 +68,7 @@ export default function PlexCollectionAddAt({
       else await api.plexCollectionAddItem(c.id, ratingKey);
       qc.setQueryData<typeof list.data>(forKey, (old) => flipContains(old, c.id));
     } catch (e) {
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     refresh();
     setBusy(false);
@@ -83,7 +84,7 @@ export default function PlexCollectionAddAt({
       made = true;
     } catch (e) {
       made = madeOnPlex(e);
-      notifyActionError(e, t("plex.collection.editFailed"));
+      notifyActionError(e, msg("plex.collection.editFailed"));
     }
     refresh();
     setBusy(false);

frontend/src/features/plexCards/PlexPlaylistAdd.tsx

@@ -12,6 +12,7 @@ import Modal from "../../components/ui/Modal";
 import { Pressable } from "../../components/ui/Pressable";
 import { Input } from "../../components/ui/Input";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // What we're adding: a single leaf (movie/episode) or a whole group (a season or an entire show, as a
 // set of episode rating_keys). Groups get a tri-state (none / some / all) per playlist.
@@ -80,7 +81,7 @@ export default function PlexPlaylistAdd({
     } catch (e) {
       notifyActionError(
         e,
-        t(allIn ? "plex.playlistAdd.removeFailed" : "plex.playlistAdd.addFailed"),
+        msg(allIn ? "plex.playlistAdd.removeFailed" : "plex.playlistAdd.addFailed"),
       );
     }
     refresh();
@@ -104,7 +105,7 @@ export default function PlexPlaylistAdd({
     } catch (e) {
       // The create may already have landed when the add fails — `refresh()` in `finally` is what
       // makes that half-done state visible instead of leaving a playlist the dialog never lists.
-      notifyActionError(e, t("plex.playlistAdd.createFailed"));
+      notifyActionError(e, msg("plex.playlistAdd.createFailed"));
     }
     refresh();
     setBusy(false);

frontend/src/features/plexCards/plexCards.lang.dom.test.tsx

@@ -74,6 +74,8 @@ describe("a season's name", () => {
     ["Season 1", 1, "plex.seasonTitle(1)"],
     ["Specials", 0, "plex.specials"],
     ["Book One: Water", 1, "Book One: Water"],
+    ["Season 4", null, "Season 4"],
+    ["", null, "plex.playlist.seasonUnknown"],
   ])("Plex's %j (season %s) reads %j", (title, n, shown) => {
     render(<SeasonCard se={season(title, n)} onOpen={vi.fn()} />);
     expect(screen.getByText(shown)).toBeTruthy();

frontend/src/features/plexCards/usePlexCardActions.tsx

@@ -10,6 +10,7 @@ import { pinPlex, useComfortPin } from "../comfort/comfortPin";
 import { useCopyItems } from "../../components/ui/copyItems";
 import PlexPlaylistAdd, { type PlexAddTarget } from "./PlexPlaylistAdd";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
+import { raw } from "../../lib/notifications";
 
 // A Plex title's ONE action list (docs/DESIGN.md "Action placement"): the right-click, the
 // long-press, Shift+F10 and the card's "…" open a menu built here, so every poster grid and rail
@@ -151,7 +152,7 @@ export function usePlexCardActions(handlers: PlexActionHandlers, open: boolean)
           ]
         : []),
       ...copy(c.title, null).map((it) => ({ ...it, separatorBefore: !onInfo })),
-      ...(withPin ? pin.item(pinPlex(c), c.title) : []),
+      ...(withPin ? pin.item(pinPlex(c), raw(c.title)) : []),
     ];
   };
 

frontend/src/features/video/AddToPlaylist.tsx

@@ -13,6 +13,7 @@ import { useAnchoredPopover } from "../../components/ui/anchoredPopoverHooks";
 import { IconButton } from "../../components/ui/IconButton";
 import { MembershipMenu } from "../../components/ui/MembershipMenu";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // A small anchored menu for toggling a video's membership in the user's playlists, with inline
 // "new playlist" creation. Its body is the shared MembershipMenu (as the channel tag editor's).
@@ -122,7 +123,7 @@ function MembershipPanel({
         old?.map((p) => (p.id === pl.id ? { ...p, has_video: !p.has_video } : p)),
       );
     } catch (e) {
-      notifyActionError(e, t(pl.has_video ? "playlists.removeFailed" : "playlists.addFailed"));
+      notifyActionError(e, msg(pl.has_video ? "playlists.removeFailed" : "playlists.addFailed"));
     }
     refresh();
     setBusy(false);
@@ -137,7 +138,7 @@ function MembershipPanel({
       await addPlaylistItem(qc, pl, videoId);
       made = true;
     } catch (e) {
-      notifyActionError(e, t("playlists.addFailed"));
+      notifyActionError(e, msg("playlists.addFailed"));
     }
     refresh();
     setBusy(false);

frontend/src/features/video/stateNotice.ts

@@ -1,5 +1,5 @@
 import i18n from "../../i18n";
-import { notify, resolveVideo } from "../../lib/notifications";
+import { msg, notify, raw, resolveVideo } from "../../lib/notifications";
 import type { Video, VideoStatus } from "../../lib/api";
 
 /** What a notice names the video by; any of it may be unknown to the surface that marked it. */
@@ -24,9 +24,9 @@ export function announceVideoState(
   const hidden = status === "hidden";
   notify({
     message: video?.title
-      ? i18n.t(hidden ? "feed.hiddenNamed" : "feed.markedWatchedNamed", { title: video.title })
-      : i18n.t(hidden ? "feed.hidden" : "feed.markedWatched"),
-    action: { label: i18n.t(hidden ? "feed.undo" : "feed.unwatch"), onClick: undo },
+      ? msg(hidden ? "feed.hiddenNamed" : "feed.markedWatchedNamed", { title: raw(video.title) })
+      : msg(hidden ? "feed.hidden" : "feed.markedWatched"),
+    action: { label: msg(hidden ? "feed.undo" : "feed.unwatch"), onClick: undo },
     meta: {
       kind: hidden ? "video-hidden" : "video-watched",
       videoId: id,

frontend/src/features/video/useVideoActions.tsx

@@ -27,6 +27,7 @@ import { useCopyItems } from "../../components/ui/copyItems";
 import { useNavigationActions } from "../navigation/navigationContext";
 import { type ActionMenuItem } from "../../components/ui/ActionMenu";
 import { VideoFollowUp, type VideoFollowUpState } from "./VideoFollowUp";
+import { raw } from "../../lib/notifications";
 
 // A video's ONE action list (docs/DESIGN.md "Action placement"). The right-click, the
 // long-press, Shift+F10 and the card's "…" all open a menu built here, so the feed, a channel page
@@ -198,7 +199,7 @@ export function useVideoActions(handlers: VideoActionHandlers, open: boolean) {
             },
           ]
         : []),
-      ...(withPin ? pin.item(pinVideo(v.id), v.title ?? "") : []),
+      ...(withPin ? pin.item(pinVideo(v.id), raw(v.title ?? "")) : []),
     ];
   };
 

frontend/src/features/wizard/OnboardingWizard.dialog.dom.test.tsx

@@ -23,7 +23,7 @@ vi.mock("../../lib/onboarding", () => ({ beginGrant: vi.fn(), endOnboarding: vi.
 
 import OnboardingWizard from "./OnboardingWizard";
 import { api, type Me } from "../../lib/api";
-import { clearAll, notify } from "../../lib/notifications";
+import { clearAll, notify, raw } from "../../lib/notifications";
 
 const me = { id: 1, email: "a@b", can_read: false, can_write: false } as unknown as Me;
 
@@ -110,7 +110,7 @@ describe("the onboarding wizard as a dialog", () => {
     document.body.appendChild(outside);
     outside.focus();
     const { unmount } = mount();
-    act(() => void notify({ level: "error", message: "offline" }));
+    act(() => void notify({ level: "error", message: raw("offline") }));
     const dismissToast = screen.getByTitle("notifications.dismiss");
     dismissToast.focus();
     expect(document.activeElement).toBe(dismissToast);
@@ -126,7 +126,7 @@ describe("the onboarding wizard as a dialog", () => {
     // unreachable from the keyboard. `ui/Modal` spans the whole dialog for exactly this reason.
     mount();
     const panel = screen.getByRole("dialog");
-    act(() => void notify({ level: "error", message: "offline" }));
+    act(() => void notify({ level: "error", message: raw("offline") }));
     try {
       const dismissToast = screen.getByTitle("notifications.dismiss");
       expect(panel.contains(dismissToast)).toBe(false);

frontend/src/i18n/backendIds.contract.test.ts

@@ -89,7 +89,7 @@ const quotaActions = enumValues("quota.py");
 // ruff wraps over several lines still matches.
 const adminCodes = [
   ...(
-    readFileSync(new URL("../lib/api/core.ts", import.meta.url), "utf-8").match(
+    readFileSync(new URL("../lib/api/refusalText.ts", import.meta.url), "utf-8").match(
       /ADMIN_REFUSALS = new Set\(\[([^\]]*)\]/,
     )?.[1] ?? ""
   ).matchAll(/"(\w+)"/g),

frontend/src/i18n/locales/en/plex.json

@@ -344,6 +344,7 @@
     "playShow": "Play the show",
     "playSeason": "Play the season",
     "removeFromPlaylist": "Remove from the playlist",
+    "seasonOfShow": "{{show}} · {{season}}",
     "removedToast": "“{{title}}” removed from the playlist",
     "undoRemoveFailed": "Couldn't put it back in the playlist"
   },

frontend/src/i18n/locales/hu/plex.json

@@ -344,6 +344,7 @@
     "playShow": "Sorozat lejátszása",
     "playSeason": "Évad lejátszása",
     "removeFromPlaylist": "Eltávolítás a listáról",
+    "seasonOfShow": "{{show}} · {{season}}",
     "removedToast": "„{{title}}” eltávolítva a listáról",
     "undoRemoveFailed": "Nem sikerült visszatenni a listára"
   },

frontend/src/lib/accountSwitchNotice.dom.test.ts

@@ -13,6 +13,7 @@ import {
   reloadAfterRefusal,
 } from "./entryUrl";
 import { HttpError } from "./api/core";
+import { raw } from "./notifications";
 
 const notice = (search: string, hash = "") =>
   accountSwitchNotice(new URLSearchParams(search), new URLSearchParams(hash));
@@ -27,13 +28,13 @@ describe("a switch of account, told to the account signed in", () => {
     expect(notice("", "access=requested&email=b%2Btag%40example.com")).toEqual({
       level: "info",
       key: "header.account.switchRequested",
-      values: { email: "b+tag@example.com" },
+      values: { email: raw("b+tag@example.com") },
     });
   });
 
   it("names the address the request lives under when that is another spelling", () => {
     expect(notice("", "access=requested&email=bob%40x.com&linked=b.ob%40x.com")?.values).toEqual({
-      email: "b.ob@x.com",
+      email: raw("b.ob@x.com"),
     });
   });
 

frontend/src/lib/actionErrors.test.ts

@@ -4,12 +4,16 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
 // Spy on the toast sink so we can assert exactly what each error maps to.
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 vi.mock("./errorDialog", () => ({ reportError: vi.fn() }));
 
 import { HttpError, api } from "./api";
 import { alreadyReported } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, raw, sayNotif } from "./notifications";
+import { localizeDetail } from "./api/refusalText";
 import { reportError } from "./errorDialog";
 import { failureReason, notifyActionError, notifyKnownFailure } from "./actionErrors";
 import i18n from "../i18n";
@@ -32,10 +36,19 @@ describe("a Plex collection name that is already taken", () => {
     );
     const err = await api.plexCreateCollection("1", "Marvel", "m1").catch((e: unknown) => e);
     notifyMock.mockClear();
-    notifyActionError(err, "EDIT_FAILED");
+    notifyActionError(err, raw("EDIT_FAILED"));
     expect(notifyMock.mock.calls).toEqual([
-      [{ level: "error", title: "EDIT_FAILED", message: i18n.t("plex.collection.nameTaken") }],
+      [
+        {
+          level: "error",
+          title: raw("EDIT_FAILED"),
+          message: { detail: { code: "collection", reason: "name_taken" } },
+        },
+      ],
     ]);
+    expect(sayNotif(notifyMock.mock.calls[0]![0].message)).toBe(
+      i18n.t("plex.collection.nameTaken"),
+    );
     expect(reportError).not.toHaveBeenCalled();
   });
 });
@@ -52,26 +65,26 @@ describe("notifyActionError", () => {
     );
     const err = await api.plexSetState("1", "watched").catch((e: unknown) => e);
     notifyMock.mockClear();
-    notifyActionError(err, "FAILED");
+    notifyActionError(err, raw("FAILED"));
     expect(notifyMock).not.toHaveBeenCalled();
   });
 
   it("does toast one the caller was left to handle", () => {
-    notifyActionError(new HttpError(404, "gone"), "FAILED");
+    notifyActionError(new HttpError(404, "gone"), raw("FAILED"));
     expect(notifyMock).toHaveBeenCalled();
   });
 
   it("reports one failure once, however many callers try", () => {
     // What keeps the app-wide mutation reporter quiet for a mutation whose own onError already spoke.
     const err = new HttpError(404, "gone");
-    notifyActionError(err, "FIRST");
-    notifyActionError(err, "SECOND");
+    notifyActionError(err, raw("FIRST"));
+    notifyActionError(err, raw("SECOND"));
     expect(notifyMock).toHaveBeenCalledTimes(1);
     expect(alreadyReported(err)).toBe(true);
   });
 
   it("says nothing about an upload the user cancelled", () => {
-    notifyActionError(new HttpError(0, "aborted"), "FAILED");
+    notifyActionError(new HttpError(0, "aborted"), raw("FAILED"));
     expect(notifyMock).not.toHaveBeenCalled();
   });
 
@@ -79,27 +92,32 @@ describe("notifyActionError", () => {
     // `reportFailure` leaves 403/404/429 to the caller, so for exactly those statuses whatever
     // English a route hand-wrote went straight into the toast — "No user with that email." in an
     // otherwise Hungarian UI, while the caller's translated fallback sat unused.
-    notifyActionError(new HttpError(404, "No user with that email."), "TRANSLATED");
+    notifyActionError(new HttpError(404, "No user with that email."), raw("TRANSLATED"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: "TRANSLATED",
-      message: i18n.t("errors.notFound.generic"),
+      title: raw("TRANSLATED"),
+      message: msg("errors.notFound.generic"),
     });
   });
 
-  it("still prefers a STRUCTURED reason, which the request layer has already localized", () => {
-    // `req` runs `{code, reason}` through localizeDetail, so `detail` is in the reader's language
-    // AND more specific than anything a status can say — quota numbers, which row is gone.
+  it("still prefers a STRUCTURED reason, kept as the refusal and said in the reader's language", () => {
+    // The notice keeps `{code, reason}` and says it through localizeDetail when shown: in the
+    // reader's language AND more specific than anything a status can say — quota numbers, which row
+    // is gone.
     const err = new HttpError(404, "Ez a csatorna már nincs a könyvtárban.", {
       code: "not_found",
       reason: "channel",
     });
-    notifyActionError(err, "TRANSLATED FALLBACK");
+    notifyActionError(err, raw("TRANSLATED FALLBACK"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: "TRANSLATED FALLBACK",
-      message: "Ez a csatorna már nincs a könyvtárban.",
+      title: raw("TRANSLATED FALLBACK"),
+      message: { detail: { code: "not_found", reason: "channel" } },
     });
+    // Said at display through localizeDetail, in the language of that moment.
+    expect(sayNotif(notifyMock.mock.calls[0]![0].message)).toBe(
+      localizeDetail({ code: "not_found", reason: "channel" }),
+    );
   });
 });
 
@@ -114,17 +132,21 @@ describe("failureReason — why a write failed, when the server did not say", ()
     [0, "errors.reason.unreachable"], // uploadReq's network failure
     [500, "errors.generic"],
   ])("a %s reads %s", (status, key) => {
-    expect(failureReason(new HttpError(status, "hand-written English"))).toBe(i18n.t(key));
+    const reason = failureReason(new HttpError(status, "hand-written English"));
+    expect(reason).toEqual(msg(key));
+    expect(sayNotif(reason)).toBe(i18n.t(key));
   });
 
   it("a request that never reached the server reads as unreachable", () => {
-    expect(failureReason(new TypeError("Failed to fetch"))).toBe(
+    expect(sayNotif(failureReason(new TypeError("Failed to fetch")))).toBe(
       i18n.t("errors.reason.unreachable"),
     );
   });
 
   it("anything else is the app's own fault, not the server's", () => {
-    expect(failureReason(new Error("key import failed"))).toBe(i18n.t("errors.reason.unexpected"));
+    expect(sayNotif(failureReason(new Error("key import failed")))).toBe(
+      i18n.t("errors.reason.unexpected"),
+    );
   });
 
   it("every reason exists in both languages", () => {
@@ -142,9 +164,9 @@ describe("failureReason — why a write failed, when the server did not say", ()
 describe("notifyKnownFailure", () => {
   it("shows the caller's specific sentence and marks the failure reported", () => {
     const err = new HttpError(409, "x", { code: "resend", reason: "email_off" });
-    notifyKnownFailure(err, "EMAIL IS OFF");
-    expect(notifyMock).toHaveBeenCalledWith({ level: "error", message: "EMAIL IS OFF" });
-    notifyActionError(err, "GENERIC");
+    notifyKnownFailure(err, raw("EMAIL IS OFF"));
+    expect(notifyMock).toHaveBeenCalledWith({ level: "error", message: raw("EMAIL IS OFF") });
+    notifyActionError(err, raw("GENERIC"));
     expect(notifyMock).toHaveBeenCalledTimes(1);
   });
 });

frontend/src/lib/actionErrors.ts

@@ -1,26 +1,24 @@
 // From the core, not the `./api` barrel: these are pure (no request), and a test that mocks the
 // barrel wholesale to stub its requests must not take the error path's own plumbing with it.
 import { alreadyReported, HttpError, isAborted, markReported } from "./api/core";
-import { notify } from "./notifications";
-import i18n from "../i18n";
+import { msg, notify, type NotifText } from "./notifications";
 
 const GATEWAY = new Set([502, 503, 504]);
 
 /**
- * WHY a write failed, in the reader's language — the line under the toast's title.
+ * WHY a write failed — the line under the toast's title, said in the reader's language when shown.
  *
- * The server's own reason wins: `req` has already run the structured detail through
- * `localizeDetail`, and it is the most specific thing there is to say (quota numbers, which row is
+ * The server's own reason wins: the structured detail, which `localizeDetail` says, and it is the most specific thing there is to say (quota numbers, which row is
  * gone). Every refusal the app answers is structured now (backend `app/refusal.py`), and a string
  * detail never reaches `HttpError.detail` (see there) — the hand-written English that once put
  * "No user with that email." into a Hungarian UI has nowhere left to come from. `detailData` still
  * gates it: status-0 errors carry a local sentinel in `detail`, not a reason. Otherwise the status
  * says it.
  */
-export function failureReason(err: unknown): string {
-  const t = i18n.t.bind(i18n);
+export function failureReason(err: unknown): NotifText {
+  const t = msg;
   if (err instanceof HttpError) {
-    if (err.detailData != null && err.detail) return err.detail;
+    if (err.detailData != null && err.detail) return { detail: err.detailData };
     // 0: `uploadReq`'s network failure. 502–504: the gateway could not reach the app. Either way the
     // change did not go through, which the connection notice alone does not say.
     if (err.status === 0 || GATEWAY.has(err.status)) return t("errors.reason.unreachable");
@@ -36,13 +34,13 @@ export function failureReason(err: unknown): string {
 
 /**
  * Surface a failed write as an error toast instead of the click silently doing nothing: the title
- * names WHAT failed (the caller's translated "Couldn't hide the channel"), the line under it says
+ * names WHAT failed (the caller's "Couldn't hide the channel"), the line under it says
  * WHY (`failureReason`). Domain-agnostic — the one way every action failure is reported, including
  * the app-wide mutation reporter in lib/queryClient.
  */
 export function notifyActionError(
   err: unknown,
-  title: string,
+  title: NotifText,
   level: "error" | "warning" = "error",
 ): void {
   // Already on screen (`req` opened the error dialog, the tab is being signed out, or a caller's own
@@ -57,7 +55,7 @@ export function notifyActionError(
  * instance cannot send email", "someone registered on that address") — shown as it is, and marked,
  * so the app-wide mutation reporter does not put a second, generic toast next to it.
  */
-export function notifyKnownFailure(err: unknown, message: string): void {
+export function notifyKnownFailure(err: unknown, message: NotifText): void {
   if (alreadyReported(err)) return;
   notify({ level: "error", message });
   markReported(err);

frontend/src/lib/api/core.test.ts

@@ -14,7 +14,12 @@ const { reportError, notify, remove, getActiveToasts } = vi.hoisted(() => ({
 }));
 
 vi.mock("../errorDialog", () => ({ reportError }));
-vi.mock("../notifications", () => ({ notify, remove, getActiveToasts }));
+vi.mock("../notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../notifications")>()),
+  notify,
+  remove,
+  getActiveToasts,
+}));
 vi.mock("../../i18n", () => ({ default: { t: (k: string) => k, language: "en" } }));
 
 import { setDebugSession } from "../log";

frontend/src/lib/api/core.ts

@@ -2,9 +2,9 @@
 // error, structured-error localization, the connectivity toast, the identity headers,
 // and the keepalive beacon. Domain modules import from here; nothing here imports a domain module,
 // so the runtime graph is a clean barrel → domain → core with no cycles.
-import { getActiveToasts, notify, remove } from "../notifications";
+import { getActiveToasts, msg, notify, remove } from "../notifications";
 import i18n from "../../i18n";
-import { formatBytes, formatDecimal } from "../format";
+import { localizeDetail } from "./refusalText";
 import { reportError } from "../errorDialog";
 import { logRequest, QUIET_HEADER, REQUEST_ID_HEADER, ROUTE_HEADER, send } from "../http";
 import { currentDebugSession, newRequestId } from "../log";
@@ -71,121 +71,6 @@ export const refusalReason = (err: unknown): string | undefined =>
     ? (err.detailData as { reason?: string } | undefined)?.reason
     : undefined;
 
-// Localize a STRUCTURED server error ({ code, reason, ... }) into the user's language. FastAPI
-// usually returns a plain string `detail`, but some routes (e.g. download quota/edit) return a
-// structured object with an i18n reason key + numbers so HU/DE users don't get hardcoded English
-// with a dot-decimal separator. Falls back to a generic message for unknown shapes.
-// The refusal codes of the admin's account and invite actions (routes/admin.py). Their reasons share
-// one namespace, `errors.admin.<reason>`, which i18n/backendIds.contract checks against the backend.
-const ADMIN_REFUSALS = new Set(["activate", "resend", "invite_send"]);
-
-function localizeDetail(d: unknown): string {
-  const t = i18n.t.bind(i18n);
-  // FastAPI request-validation errors: `detail` is an ARRAY of { loc, msg, type }. The UI sends
-  // well-formed requests, so this only fires on genuinely malformed input. The per-field `msg` and
-  // `loc` field names are English, snake_case internal tokens — surface a clean, fully localized
-  // "check your input" message rather than leaking them into a translated sentence.
-  if (Array.isArray(d)) return t("errors.validation");
-  const o = d as
-    | { code?: string; reason?: string; limit?: number; limit_s?: number; min?: number }
-    | null
-    | undefined;
-  if (o?.code === "quota") {
-    if (o.reason === "max_bytes") {
-      const gb = formatDecimal((o.limit || 0) / 1_073_741_824, i18n.language, 1, 0);
-      return t("downloads.errors.quota.max_bytes", { size: gb });
-    }
-    if (o.reason === "max_jobs") return t("downloads.errors.quota.max_jobs", { limit: o.limit });
-    return t("downloads.errors.quota.generic");
-  }
-  if (o?.code === "edit")
-    return t(`downloads.errors.edit.${o.reason}`, t("downloads.errors.edit.generic"));
-  // A clip the server will not cut (downloads/clip): the range, the frame, the source. An unknown
-  // reason reads as the plain failure rather than a key; a cap comes with the refusal (`limit_s`).
-  if (o?.code === "clip")
-    return t(`clip.errors.${o.reason}`, {
-      defaultValue: t("clip.failed"),
-      minutes: o.limit_s == null ? undefined : formatDecimal(o.limit_s / 60, i18n.language, 1, 0),
-    });
-  if (o?.code === "cookies")
-    return t(`downloads.errors.cookies.${o.reason}`, t("downloads.errors.cookies.generic"));
-  // Password sign-in refusals. The card renders the account-shaped ones as a full panel
-  // off `detailData`; this is the one-line form every other consumer (and the card's own fallback)
-  // gets. A reason this build doesn't know falls through to the generic message rather than showing
-  // a raw key, which is what an i18n miss would otherwise put on screen.
-  if (o?.code === "login")
-    return t(`welcome.auth.blocked.${o.reason}.short`, t("welcome.auth.genericError"));
-  // The two email-link confirmations. Their failure is one a user meets by simply clicking an old
-  // link, so it is the last place that may answer in hardcoded English under a bilingual UI.
-  if (o?.code === "verify") return t("welcome.auth.verifyInvalid");
-  if (o?.code === "reset")
-    return o.reason === "weak_password"
-      ? t("welcome.auth.weakPassword", { min: o.limit ?? o.min })
-      : t("welcome.auth.deadLink.short");
-  // Local-upload ingest: the per-file cap carries the limit in bytes; empty is a bare code.
-  if (o?.code === "upload_too_large")
-    return t("downloads.errors.upload.tooLarge", { size: formatBytes(o.limit, i18n.language) });
-  if (o?.code === "upload_empty") return t("downloads.errors.upload.empty");
-  // The EDGE ceiling's refusal (`bodylimit.TOO_LARGE_BODY`), shared by every route and carrying no
-  // number. Not a theoretical case: on a DEFAULT install it is what an over-cap upload gets,
-  // because the ceiling and the route's own cap are the same figure and the edge answers first —
-  // the route's numbered `upload_too_large` above is the answer only once an admin has LOWERED the
-  // knob (see bodylimit.ROUTE_MAX_BODY_BYTES). Without this branch that refusal fell through to
-  // the generic "couldn't carry out that action", the one message no retry can fix.
-  //
-  // A BACKSTOP, not the plan. The middleware answers without draining, so whether the browser gets
-  // to read this at all depends on the client having finished sending: measured readable up to
-  // 200 MiB over loopback, and measured as a bare `onerror` through a dev proxy. That is why the
-  // upload dialog checks the file against `upload_max_bytes` BEFORE sending — this branch is what
-  // happens when that check could not run.
-  //
-  // `errors.tooLarge` stays PAYLOAD-NEUTRAL for that reason. It is also what a JSON form gets
-  // (`debug_sessions` refuses an over-size draft with the same bare code), so wording it as advice
-  // about a file told the issue composer's user to pick a smaller one — of nothing. The
-  // file-specific sentence is `downloads.errors.upload.tooLarge`, one branch up, which has a number.
-  if (o?.code === "too_large") return t("errors.tooLarge");
-  // SEC-12: a download URL the server refuses to fetch. The reasons are deliberately distinct —
-  // "we could not look that host up" is a different thing to tell someone than "we will not fetch
-  // from that address" — so an unknown reason falls back to the generic refusal rather than a key.
-  if (o?.code === "url_blocked")
-    return t(`downloads.errors.urlBlocked.${o.reason}`, t("downloads.errors.urlBlocked.generic"));
-  // The one-step "move to another list". Both reasons mean the same thing to a reader —
-  // the list moved under you — but they are different enough to be worth naming separately, and an
-  // unknown reason falls back to the plain failure rather than printing a key.
-  if (o?.code === "playlist_move")
-    return t(`playlists.moveErrors.${o.reason}`, t("playlists.moveFailed"));
-  // A Plex collection name already taken in that library (the one collection-edit refusal).
-  if (o?.code === "collection")
-    return o.reason === "name_taken"
-      ? t("plex.collection.nameTaken")
-      : t("plex.collection.editFailed");
-  // An action YouTube refused (routes/_common.youtube_refusal): what the reader can do about it —
-  // wait for the budget, reconnect, or retry. An unknown reason reads as the retryable one.
-  if (o?.code === "youtube")
-    return t(`errors.youtube.${o.reason}`, t("errors.youtube.unavailable"));
-  // Every other refusal (backend `app/refusal.py`): one family, the reason naming the sentence and
-  // the rest of the detail its values (`{{min}}`, `{{name}}`, …). A reason this build does not know
-  // reads as the generic failure rather than a key.
-  if (o?.code === "refused")
-    return t(`errors.refused.${o.reason}`, { ...o, defaultValue: t("errors.generic") });
-  // A playlist action the server refused (Watch later can't be deleted, YouTube said no, …).
-  if (o?.code === "playlist") return t(`playlists.errors.${o.reason}`, t("errors.generic"));
-  // An admin action on an account or an invite that the server refused: activating an address that
-  // is no longer approved, a confirmation link or invitation with nothing to go to or no mail to go
-  // by. The toast's title already names the button; this is the WHY, and it used to be the generic
-  // "try again", which no retry could fix.
-  if (ADMIN_REFUSALS.has(o?.code ?? "")) return t(`errors.admin.${o?.reason}`, t("errors.generic"));
-  // Any row that is gone — deleted in another tab or device, or never the caller's (a stranger's
-  // row 404s the same way). `reason` names WHAT is gone; one this build doesn't know says it
-  // generically rather than printing a key.
-  if (o?.code === "not_found")
-    return t(`errors.notFound.${o.reason}`, t("errors.notFound.generic"));
-  // SEC-14: a manual sync trigger on cooldown. Not an error the user caused so much as a pace
-  // limit, and the copy says so.
-  if (o?.code === "sync_cooldown") return t("errors.syncCooldown");
-  return t("errors.generic");
-}
-
 // A single, self-resolving "connection lost" status: while the server is unreachable we
 // show one sticky, transient (non-persisted) notice; the moment any request reaches the
 // server again we remove it. This makes good on its "clears once it's back" copy and keeps
@@ -199,8 +84,8 @@ function markConnectivityLost(): void {
   if (id !== null) remove(id);
   connectivityNotifId = notify({
     level: "error",
-    title: i18n.t("errors.offline.title"),
-    message: i18n.t("errors.offline.body"),
+    title: msg("errors.offline.title"),
+    message: msg("errors.offline.body"),
     transient: true,
   });
 }

frontend/src/lib/api/diagnostics.dom.test.ts

@@ -7,7 +7,8 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
 vi.mock("../errorDialog", () => ({ reportError: vi.fn() }));
-vi.mock("../notifications", () => ({
+vi.mock("../notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../notifications")>()),
   notify: vi.fn(() => 1),
   remove: vi.fn(),
   getActiveToasts: vi.fn((): { id: number }[] => []),

frontend/src/lib/api/refusalText.ts

@@ -0,0 +1,120 @@
+// A server refusal ({ code, reason, … }) in the reader's language. Its own module, not the request
+// core's: a notice keeps the refusal it reports and says it again at display, in the language of the
+// moment, and the notice store cannot import the request core that imports it.
+import i18n from "../../i18n";
+import { formatBytes, formatDecimal } from "../format";
+
+// Localize a STRUCTURED server error ({ code, reason, ... }) into the user's language. FastAPI
+// usually returns a plain string `detail`, but some routes (e.g. download quota/edit) return a
+// structured object with an i18n reason key + numbers so HU/DE users don't get hardcoded English
+// with a dot-decimal separator. Falls back to a generic message for unknown shapes.
+// The refusal codes of the admin's account and invite actions (routes/admin.py). Their reasons share
+// one namespace, `errors.admin.<reason>`, which i18n/backendIds.contract checks against the backend.
+const ADMIN_REFUSALS = new Set(["activate", "resend", "invite_send"]);
+
+export function localizeDetail(d: unknown): string {
+  const t = i18n.t.bind(i18n);
+  // FastAPI request-validation errors: `detail` is an ARRAY of { loc, msg, type }. The UI sends
+  // well-formed requests, so this only fires on genuinely malformed input. The per-field `msg` and
+  // `loc` field names are English, snake_case internal tokens — surface a clean, fully localized
+  // "check your input" message rather than leaking them into a translated sentence.
+  if (Array.isArray(d)) return t("errors.validation");
+  const o = d as
+    | { code?: string; reason?: string; limit?: number; limit_s?: number; min?: number }
+    | null
+    | undefined;
+  if (o?.code === "quota") {
+    if (o.reason === "max_bytes") {
+      const gb = formatDecimal((o.limit || 0) / 1_073_741_824, i18n.language, 1, 0);
+      return t("downloads.errors.quota.max_bytes", { size: gb });
+    }
+    if (o.reason === "max_jobs") return t("downloads.errors.quota.max_jobs", { limit: o.limit });
+    return t("downloads.errors.quota.generic");
+  }
+  if (o?.code === "edit")
+    return t(`downloads.errors.edit.${o.reason}`, t("downloads.errors.edit.generic"));
+  // A clip the server will not cut (downloads/clip): the range, the frame, the source. An unknown
+  // reason reads as the plain failure rather than a key; a cap comes with the refusal (`limit_s`).
+  if (o?.code === "clip")
+    return t(`clip.errors.${o.reason}`, {
+      defaultValue: t("clip.failed"),
+      minutes: o.limit_s == null ? undefined : formatDecimal(o.limit_s / 60, i18n.language, 1, 0),
+    });
+  if (o?.code === "cookies")
+    return t(`downloads.errors.cookies.${o.reason}`, t("downloads.errors.cookies.generic"));
+  // Password sign-in refusals. The card renders the account-shaped ones as a full panel
+  // off `detailData`; this is the one-line form every other consumer (and the card's own fallback)
+  // gets. A reason this build doesn't know falls through to the generic message rather than showing
+  // a raw key, which is what an i18n miss would otherwise put on screen.
+  if (o?.code === "login")
+    return t(`welcome.auth.blocked.${o.reason}.short`, t("welcome.auth.genericError"));
+  // The two email-link confirmations. Their failure is one a user meets by simply clicking an old
+  // link, so it is the last place that may answer in hardcoded English under a bilingual UI.
+  if (o?.code === "verify") return t("welcome.auth.verifyInvalid");
+  if (o?.code === "reset")
+    return o.reason === "weak_password"
+      ? t("welcome.auth.weakPassword", { min: o.limit ?? o.min })
+      : t("welcome.auth.deadLink.short");
+  // Local-upload ingest: the per-file cap carries the limit in bytes; empty is a bare code.
+  if (o?.code === "upload_too_large")
+    return t("downloads.errors.upload.tooLarge", { size: formatBytes(o.limit, i18n.language) });
+  if (o?.code === "upload_empty") return t("downloads.errors.upload.empty");
+  // The EDGE ceiling's refusal (`bodylimit.TOO_LARGE_BODY`), shared by every route and carrying no
+  // number. Not a theoretical case: on a DEFAULT install it is what an over-cap upload gets,
+  // because the ceiling and the route's own cap are the same figure and the edge answers first —
+  // the route's numbered `upload_too_large` above is the answer only once an admin has LOWERED the
+  // knob (see bodylimit.ROUTE_MAX_BODY_BYTES). Without this branch that refusal fell through to
+  // the generic "couldn't carry out that action", the one message no retry can fix.
+  //
+  // A BACKSTOP, not the plan. The middleware answers without draining, so whether the browser gets
+  // to read this at all depends on the client having finished sending: measured readable up to
+  // 200 MiB over loopback, and measured as a bare `onerror` through a dev proxy. That is why the
+  // upload dialog checks the file against `upload_max_bytes` BEFORE sending — this branch is what
+  // happens when that check could not run.
+  //
+  // `errors.tooLarge` stays PAYLOAD-NEUTRAL for that reason. It is also what a JSON form gets
+  // (`debug_sessions` refuses an over-size draft with the same bare code), so wording it as advice
+  // about a file told the issue composer's user to pick a smaller one — of nothing. The
+  // file-specific sentence is `downloads.errors.upload.tooLarge`, one branch up, which has a number.
+  if (o?.code === "too_large") return t("errors.tooLarge");
+  // SEC-12: a download URL the server refuses to fetch. The reasons are deliberately distinct —
+  // "we could not look that host up" is a different thing to tell someone than "we will not fetch
+  // from that address" — so an unknown reason falls back to the generic refusal rather than a key.
+  if (o?.code === "url_blocked")
+    return t(`downloads.errors.urlBlocked.${o.reason}`, t("downloads.errors.urlBlocked.generic"));
+  // The one-step "move to another list". Both reasons mean the same thing to a reader —
+  // the list moved under you — but they are different enough to be worth naming separately, and an
+  // unknown reason falls back to the plain failure rather than printing a key.
+  if (o?.code === "playlist_move")
+    return t(`playlists.moveErrors.${o.reason}`, t("playlists.moveFailed"));
+  // A Plex collection name already taken in that library (the one collection-edit refusal).
+  if (o?.code === "collection")
+    return o.reason === "name_taken"
+      ? t("plex.collection.nameTaken")
+      : t("plex.collection.editFailed");
+  // An action YouTube refused (routes/_common.youtube_refusal): what the reader can do about it —
+  // wait for the budget, reconnect, or retry. An unknown reason reads as the retryable one.
+  if (o?.code === "youtube")
+    return t(`errors.youtube.${o.reason}`, t("errors.youtube.unavailable"));
+  // Every other refusal (backend `app/refusal.py`): one family, the reason naming the sentence and
+  // the rest of the detail its values (`{{min}}`, `{{name}}`, …). A reason this build does not know
+  // reads as the generic failure rather than a key.
+  if (o?.code === "refused")
+    return t(`errors.refused.${o.reason}`, { ...o, defaultValue: t("errors.generic") });
+  // A playlist action the server refused (Watch later can't be deleted, YouTube said no, …).
+  if (o?.code === "playlist") return t(`playlists.errors.${o.reason}`, t("errors.generic"));
+  // An admin action on an account or an invite that the server refused: activating an address that
+  // is no longer approved, a confirmation link or invitation with nothing to go to or no mail to go
+  // by. The toast's title already names the button; this is the WHY, and it used to be the generic
+  // "try again", which no retry could fix.
+  if (ADMIN_REFUSALS.has(o?.code ?? "")) return t(`errors.admin.${o?.reason}`, t("errors.generic"));
+  // Any row that is gone — deleted in another tab or device, or never the caller's (a stranger's
+  // row 404s the same way). `reason` names WHAT is gone; one this build doesn't know says it
+  // generically rather than printing a key.
+  if (o?.code === "not_found")
+    return t(`errors.notFound.${o.reason}`, t("errors.notFound.generic"));
+  // SEC-14: a manual sync trigger on cooldown. Not an error the user caused so much as a pace
+  // limit, and the copy says so.
+  if (o?.code === "sync_cooldown") return t("errors.syncCooldown");
+  return t("errors.generic");
+}

frontend/src/lib/channelWriteFailures.dom.test.tsx

@@ -9,13 +9,15 @@ import type { ReactNode } from "react";
 import { act, renderHook, waitFor } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 
 import { api, HttpError } from "./api";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 import { useChannelTagActions } from "./useChannelTagActions";
 import { useChannelPriority } from "./useChannelPriority";
-import i18n from "../i18n";
 
 const notifyMock = vi.mocked(notify);
 beforeEach(() => notifyMock.mockClear());
@@ -37,8 +39,8 @@ describe("useChannelTagActions", () => {
     await waitFor(() => expect(onError).toHaveBeenCalledWith("UC1"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("channels.tags.updateFailed"),
-      message: i18n.t("errors.reason.forbidden"),
+      title: msg("channels.tags.updateFailed"),
+      message: msg("errors.reason.forbidden"),
     });
   });
 
@@ -52,8 +54,8 @@ describe("useChannelTagActions", () => {
     await waitFor(() =>
       expect(notifyMock).toHaveBeenCalledWith({
         level: "error",
-        title: i18n.t("channels.tags.createFailed"),
-        message: i18n.t("errors.reason.rateLimited"),
+        title: msg("channels.tags.createFailed"),
+        message: msg("errors.reason.rateLimited"),
       }),
     );
   });
@@ -76,8 +78,8 @@ describe("useChannelPriority", () => {
     await waitFor(() => expect(onError).toHaveBeenCalledWith("UC1"));
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("errors.writeFailed.channelPriority"),
-      message: i18n.t("errors.reason.unreachable"),
+      title: msg("errors.writeFailed.channelPriority"),
+      message: msg("errors.reason.unreachable"),
     });
   });
 });

frontend/src/lib/claimedStores.dom.test.ts

@@ -5,11 +5,12 @@
 // notification store used to keep its empty, nobody's history, and the tab's first notice replaced the
 // account's stored history with it.
 import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { raw, sayNotif, type NotifText } from "./notifications";
 
 const entry = (id: number, message: string) => ({
   id,
   level: "info",
-  message,
+  message: raw(message),
   ts: 1,
   read: true,
   dismissed: true,
@@ -19,10 +20,10 @@ const entry = (id: number, message: string) => ({
 });
 const storedMessages = () =>
   (
-    JSON.parse(localStorage.getItem("siftlode.notifications") ?? "[]") as {
-      message: string;
+    JSON.parse(localStorage.getItem("siftlode.notifHistory") ?? "[]") as {
+      message: NotifText;
     }[]
-  ).map((n) => n.message);
+  ).map((n) => sayNotif(n.message));
 
 // Warm the transform cache once (see verifyEntry.dom.test.tsx): the first cold import costs ~0.8 s
 // alone and outran the 5 s case timeout under a full coverage run. Transformed code outlives
@@ -47,14 +48,14 @@ beforeEach(() => {
 describe("stores read at import, before the account is known", { timeout: CASE_BUDGET }, () => {
   it("keep the account's notification history and settings once it is claimed", async () => {
     localStorage.setItem("siftlode.owner", "5");
-    localStorage.setItem("siftlode.notifications", JSON.stringify([entry(7, "older")]));
+    localStorage.setItem("siftlode.notifHistory", JSON.stringify([entry(7, "older")]));
     localStorage.setItem("siftlode.notifSettings", JSON.stringify({ durationMs: 0 }));
     const notifications = await import("./notifications");
     const { claimLocalData } = await import("./storage");
 
-    notifications.notify({ message: "before the claim" }); // e.g. a failed boot probe
+    notifications.notify({ message: raw("before the claim") }); // e.g. a failed boot probe
     claimLocalData(5);
-    notifications.notify({ message: "after the claim" });
+    notifications.notify({ message: raw("after the claim") });
 
     expect(storedMessages()).toEqual(["older", "before the claim", "after the claim"]);
     expect(notifications.getNotifSettings().durationMs).toBe(0);
@@ -75,12 +76,12 @@ describe("stores read at import, before the account is known", { timeout: CASE_B
 describe("a browser that held another account's state", { timeout: CASE_BUDGET }, () => {
   it("starts the new account's notices from an empty history", async () => {
     localStorage.setItem("siftlode.owner", "4");
-    localStorage.setItem("siftlode.notifications", JSON.stringify([entry(7, "four's")]));
+    localStorage.setItem("siftlode.notifHistory", JSON.stringify([entry(7, "four's")]));
     const notifications = await import("./notifications");
     const { claimLocalData } = await import("./storage");
 
     claimLocalData(5);
-    notifications.notify({ message: "as five" });
+    notifications.notify({ message: raw("as five") });
 
     expect(storedMessages()).toEqual(["as five"]);
   });

frontend/src/lib/downloads.test.ts

@@ -21,18 +21,21 @@ vi.mock("./api", () => ({
   api: { downloadLinks, createDownloadLink, folderLinks, createFolderLink },
 }));
 vi.mock("./clipboard", () => ({ copyText }));
-vi.mock("./notifications", () => ({ notify }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify,
+}));
 
 import { quickShareLink } from "./downloads";
 import { qk } from "./queryKeys";
+import { msg, type NotifText } from "./notifications";
 
-const t = (k: string) => k;
 const origin = window.location.origin;
 
 type ToastArg = {
   level: string;
-  message: string;
-  action?: { label: string; onClick: () => void };
+  message: NotifText;
+  action?: { label: NotifText; onClick: () => void };
 };
 const firstToast = () => notify.mock.calls[0]![0] as ToastArg;
 
@@ -55,7 +58,7 @@ describe("quickShareLink", () => {
     createDownloadLink.mockResolvedValue({ id: 7, url: "/watch/tok7" });
     const openSpy = vi.spyOn(window, "open").mockReturnValue(null);
 
-    const url = await quickShareLink(qc(), { kind: "file", id: 42 }, t);
+    const url = await quickShareLink(qc(), { kind: "file", id: 42 });
 
     expect(url).toBe(`${origin}/watch/tok7`);
     // Minted with an EMPTY body so the backend default (allow_download=true) applies.
@@ -63,8 +66,8 @@ describe("quickShareLink", () => {
     expect(copyText).toHaveBeenCalledWith(`${origin}/watch/tok7`);
     const arg = firstToast();
     expect(arg.level).toBe("success");
-    expect(arg.message).toBe("downloads.share.linkCopied");
-    expect(arg.action!.label).toBe("downloads.share.openNewTab");
+    expect(arg.message).toEqual(msg("downloads.share.linkCopied"));
+    expect(arg.action!.label).toEqual(msg("downloads.share.openNewTab"));
     arg.action!.onClick();
     expect(openSpy).toHaveBeenCalledWith(`${origin}/watch/tok7`, "_blank", "noopener,noreferrer");
   });
@@ -72,7 +75,7 @@ describe("quickShareLink", () => {
   it("reuses an existing link instead of minting a duplicate", async () => {
     downloadLinks.mockResolvedValue([{ id: 3, url: "/watch/old" }]);
 
-    const url = await quickShareLink(qc(), { kind: "file", id: 1 }, t);
+    const url = await quickShareLink(qc(), { kind: "file", id: 1 });
 
     expect(url).toBe(`${origin}/watch/old`);
     expect(createDownloadLink).not.toHaveBeenCalled();
@@ -85,7 +88,7 @@ describe("quickShareLink", () => {
       { id: 3, url: "/watch/older" },
     ]);
 
-    const url = await quickShareLink(qc(), { kind: "file", id: 1 }, t);
+    const url = await quickShareLink(qc(), { kind: "file", id: 1 });
 
     expect(url).toBe(`${origin}/watch/older`);
     expect(createDownloadLink).not.toHaveBeenCalled();
@@ -97,7 +100,7 @@ describe("quickShareLink", () => {
     createDownloadLink.mockResolvedValue({ id: 8, url: "/watch/new" });
     const client = qc();
 
-    const url = await quickShareLink(client, { kind: "file", id: 6 }, t);
+    const url = await quickShareLink(client, { kind: "file", id: 6 });
 
     expect(url).toBe(`${origin}/watch/new`);
     expect(copyText).toHaveBeenCalledWith(`${origin}/watch/new`);
@@ -113,7 +116,7 @@ describe("quickShareLink", () => {
     const client = qc();
     client.setQueryData(qk.fileFolders(), []);
 
-    const url = await quickShareLink(client, { kind: "folder", id: 5 }, t);
+    const url = await quickShareLink(client, { kind: "folder", id: 5 });
 
     expect(url).toBe(`${origin}/watch/fold`);
     expect(folderLinks).toHaveBeenCalledWith(5);
@@ -129,26 +132,26 @@ describe("quickShareLink", () => {
     downloadLinks.mockResolvedValue([{ id: 5, url: "/watch/x" }]);
     copyText.mockResolvedValue(false);
 
-    const url = await quickShareLink(qc(), { kind: "file", id: 2 }, t);
+    const url = await quickShareLink(qc(), { kind: "file", id: 2 });
 
     expect(url).toBe(`${origin}/watch/x`); // the link is never a dead end
     const arg = firstToast();
     expect(arg.level).toBe("warning");
-    expect(arg.message).toBe("downloads.share.copyFailed");
-    expect(arg.action!.label).toBe("downloads.share.openNewTab");
+    expect(arg.message).toEqual(msg("downloads.share.copyFailed"));
+    expect(arg.action!.label).toEqual(msg("downloads.share.openNewTab"));
   });
 
   it("reports an error and returns null when link creation fails", async () => {
     downloadLinks.mockResolvedValue([]);
     createDownloadLink.mockRejectedValue(new Error("boom"));
 
-    const url = await quickShareLink(qc(), { kind: "file", id: 9 }, t);
+    const url = await quickShareLink(qc(), { kind: "file", id: 9 });
 
     expect(url).toBeNull();
     expect(copyText).not.toHaveBeenCalled();
     // Titled with what failed, and carrying why (notifyActionError), not a bare message.
     expect(notify).toHaveBeenCalledWith(
-      expect.objectContaining({ level: "error", title: "downloads.share.linkFailed" }),
+      expect.objectContaining({ level: "error", title: msg("downloads.share.linkFailed") }),
     );
   });
 });

frontend/src/lib/downloads.ts

@@ -2,7 +2,7 @@ import type { QueryClient } from "@tanstack/react-query";
 import { qk } from "./queryKeys";
 import { api, type NewShareLink } from "./api";
 import { copyText } from "./clipboard";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 import { notifyActionError } from "./actionErrors";
 
 // The download queue, the per-card download index, the library (its listings and folder counts) and
@@ -44,11 +44,7 @@ export function invalidateLinks(qc: QueryClient, target: LinkTarget) {
 // new tab" action. A copy failure still toasts (warning) WITH that action, so the link is never a dead
 // end. Advanced controls (password, expiry, revoke, share-with-a-user) live in the Share dialog.
 // Returns the shared URL, or null if link creation failed — so the caller/tests can react to the outcome.
-export async function quickShareLink(
-  qc: QueryClient,
-  target: LinkTarget,
-  t: (key: string) => string,
-): Promise<string | null> {
+export async function quickShareLink(qc: QueryClient, target: LinkTarget): Promise<string | null> {
   let path;
   try {
     const existing = await qc.fetchQuery({
@@ -65,18 +61,18 @@ export async function quickShareLink(
     }
     if (!path) throw new Error("the new link came back without its address");
   } catch (e) {
-    notifyActionError(e, t("downloads.share.linkFailed"));
+    notifyActionError(e, msg("downloads.share.linkFailed"));
     return null;
   }
   const url = window.location.origin + path;
   const action = {
-    label: t("downloads.share.openNewTab"),
+    label: msg("downloads.share.openNewTab"),
     onClick: () => window.open(url, "_blank", "noopener,noreferrer"),
   };
   notify(
     (await copyText(url))
-      ? { level: "success", message: t("downloads.share.linkCopied"), action }
-      : { level: "warning", message: t("downloads.share.copyFailed"), action },
+      ? { level: "success", message: msg("downloads.share.linkCopied"), action }
+      : { level: "warning", message: msg("downloads.share.copyFailed"), action },
   );
   return url;
 }

frontend/src/lib/entryUrl.ts

@@ -14,7 +14,7 @@
 // names) — an email in a query string lands in every reverse-proxy access log. Plain status flags
 // with nothing personal in them (login, deleted, account) ride the query string.
 
-import type { NotifLevel } from "./notifications";
+import { raw, type NotifLevel, type NotifValue } from "./notifications";
 import { refusalReason } from "./api/core";
 import { hrefHere } from "./urlState";
 
@@ -88,7 +88,7 @@ export function clearEntryUrl(): void {
 export interface AccountNotice {
   level: NotifLevel;
   key: string;
-  values?: Record<string, string>;
+  values?: Record<string, NotifValue>;
 }
 
 /** What the entry URL says to the account signed in here about a switch of account. A sign-in as
@@ -110,7 +110,7 @@ export function accountSwitchNotice(
   const access = hash.get("access");
   const email = hash.get("linked") || hash.get("email");
   if (access === "requested" && email)
-    return { level: "info", key: "header.account.switchRequested", values: { email } };
+    return { level: "info", key: "header.account.switchRequested", values: { email: raw(email) } };
   if (access === "requested" || access === "denied")
     return { level: "warning", key: "header.account.switchNotApproved" };
   return null;

frontend/src/lib/notifHistory.dom.test.ts

@@ -0,0 +1,72 @@
+// @vitest-environment jsdom
+//
+// The notice history changed shape (a notice keeps what to say, not the said text). A build from
+// before it reads the old key and renders its rows as text, so an object there crashed its
+// Notifications page after a rollback. The history now lives under a key of its own: the old one is
+// read once, while the new one does not exist yet, and never written.
+import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import { msg, raw, sayNotif, type NotifText } from "./notifications";
+
+const OLD_KEY = "siftlode.notifications";
+
+// A row as the build before wrote it: its text already said.
+const oldRow = (id: number, message: string) => ({
+  id,
+  level: "info",
+  message,
+  ts: 1,
+  read: true,
+  dismissed: true,
+  transient: false,
+  repeat: 1,
+  requiresInteraction: false,
+});
+
+const saidHistory = (key: string) =>
+  (JSON.parse(localStorage.getItem(key) ?? "[]") as { message: NotifText }[]).map((n) =>
+    sayNotif(n.message),
+  );
+
+beforeAll(async () => {
+  await import("./notifications");
+  await import("./storage");
+}, 60_000);
+
+beforeEach(() => {
+  localStorage.clear();
+  sessionStorage.clear();
+  vi.resetModules(); // the store loads at import: each case needs a fresh one
+});
+
+describe("the notice history's own key", { timeout: 30_000 }, () => {
+  it("carries the old history forward and leaves the old key as the build before wrote it", async () => {
+    const old = JSON.stringify([oldRow(7, "older")]);
+    localStorage.setItem("siftlode.owner", "5");
+    localStorage.setItem(OLD_KEY, old);
+    const notifications = await import("./notifications");
+    const { claimLocalData, LS } = await import("./storage");
+
+    claimLocalData(5);
+    notifications.notify({ message: msg("common.copy.done") });
+
+    expect(LS.notifHistory).not.toBe(OLD_KEY);
+    expect(localStorage.getItem(OLD_KEY)).toBe(old);
+    expect(saidHistory(LS.notifHistory)).toEqual(["older", "Copied to the clipboard"]);
+  });
+
+  it("reads the old key only while the new one does not exist", async () => {
+    const { LS } = await import("./storage");
+    localStorage.setItem("siftlode.owner", "5");
+    localStorage.setItem(OLD_KEY, JSON.stringify([oldRow(7, "older")]));
+    localStorage.setItem(
+      LS.notifHistory,
+      JSON.stringify([{ ...oldRow(8, ""), message: raw("newer") }]),
+    );
+    const notifications = await import("./notifications");
+    const { claimLocalData } = await import("./storage");
+
+    claimLocalData(5);
+
+    expect(notifications.getNotifications().map((n) => sayNotif(n.message))).toEqual(["newer"]);
+  });
+});

frontend/src/lib/notifText.contract.test.ts

@@ -0,0 +1,73 @@
+import { describe, expect, it } from "vitest";
+import ts from "typescript";
+import { readSources } from "./rawSources.testkit";
+
+// A notice says WHAT to say (lib/notifications NotifText) and is said when shown; a plain `t()` says
+// it now. tsc cannot tell the two apart where they meet — `msg`'s key is a string, `detail` is
+// unknown, and i18next's options take any value — so the slips are caught here, on the syntax:
+// - a NotifText handed to `t()` as a value (`t("k", { name: raw(x) })`) reads "[object Object]";
+// - an already-said text kept in a notice (`msg(t("k"))`, `raw(t("k"))`, `{ detail: t("k") }`)
+//   stays in the language it was raised in.
+
+const isT = (e: ts.Expression) =>
+  (ts.isIdentifier(e) && e.text === "t") ||
+  (ts.isPropertyAccessExpression(e) && e.name.text === "t");
+const isCallTo = (e: ts.Node, names: string[]): e is ts.CallExpression =>
+  ts.isCallExpression(e) && ts.isIdentifier(e.expression) && names.includes(e.expression.text);
+const isTCall = (e: ts.Node): e is ts.CallExpression => ts.isCallExpression(e) && isT(e.expression);
+
+function mixedNotifText(name: string, src: string): string[] {
+  const file = ts.createSourceFile(name, src, ts.ScriptTarget.Latest, true, ts.ScriptKind.TSX);
+  const out: string[] = [];
+  const at = (n: ts.Node, what: string) =>
+    out.push(`${name}:${file.getLineAndCharacterOfPosition(n.getStart()).line + 1} ${what}`);
+  const visit = (n: ts.Node) => {
+    if (isTCall(n)) {
+      for (const arg of n.arguments.slice(1)) {
+        if (!ts.isObjectLiteralExpression(arg)) continue;
+        for (const p of arg.properties) {
+          if (ts.isPropertyAssignment(p) && isCallTo(p.initializer, ["raw", "msg"]))
+            at(p, "a notice value handed to t()");
+        }
+      }
+    }
+    if (isCallTo(n, ["msg", "raw"]) && n.arguments[0] && isTCall(n.arguments[0]))
+      at(n, "a said text kept in a notice");
+    if (
+      ts.isPropertyAssignment(n) &&
+      ts.isIdentifier(n.name) &&
+      n.name.text === "detail" &&
+      isTCall(n.initializer)
+    )
+      at(n, "a said text kept as a notice's detail");
+    ts.forEachChild(n, visit);
+  };
+  visit(file);
+  return out;
+}
+
+describe("a notice's text and a plain t() do not mix", () => {
+  it("holds across src", () => {
+    const files = readSources(__dirname, ["../**/*.ts", "../**/*.tsx", "!../**/*.test.*"]);
+    expect(Object.keys(files).length).toBeGreaterThan(100); // the glob matched the app
+    expect(Object.entries(files).flatMap(([p, src]) => mixedNotifText(p, src))).toEqual([]);
+  });
+
+  it.each([
+    ['t("users.delete.confirm", { email: raw(u.email) })', "a notice value handed to t()"],
+    ['i18n.t("k", { n: msg("x") })', "a notice value handed to t()"],
+    ['notify({ message: msg(t("feed.saved")) })', "a said text kept in a notice"],
+    ['notify({ message: raw(t("feed.saved")) })', "a said text kept in a notice"],
+    ['notify({ message: { detail: t("x") } })', "a said text kept as a notice's detail"],
+  ])("sees %s", (src, what) => {
+    expect(mixedNotifText("x.tsx", src)).toEqual([`x.tsx:1 ${what}`]);
+  });
+
+  it.each([
+    'msg("channels.discovery.subscribedBody", { name: raw(nameOf(c)) })',
+    't("channels.discovery.confirmSubscribe", { name: nameOf(c) })',
+    "sayNotif(msg(key), t)",
+  ])("lets %s through", (src) => {
+    expect(mixedNotifText("x.tsx", src)).toEqual([]);
+  });
+});

frontend/src/lib/notifications.actionTtl.dom.test.ts

@@ -10,6 +10,7 @@ import {
   configureNotifications,
   getActiveToasts,
   notify,
+  raw,
 } from "./notifications";
 
 beforeEach(() => vi.useFakeTimers());
@@ -19,14 +20,14 @@ afterEach(() => {
   vi.useRealTimers();
 });
 
-const undo = { label: "Undo", onClick: () => {} };
+const undo = { label: raw("Undo"), onClick: () => {} };
 const shown = (id: number) => getActiveToasts().some((n) => n.id === id);
 
 describe("an action toast's lifetime", () => {
   it("stays for the floor when the reader's toasts last 3 s", () => {
     configureNotifications({ durationMs: 3000 });
-    const plain = notify({ message: "plain" });
-    const withUndo = notify({ message: "removed", action: undo });
+    const plain = notify({ message: raw("plain") });
+    const withUndo = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(3001);
     expect(shown(plain)).toBe(false);
     expect(shown(withUndo)).toBe(true);
@@ -36,7 +37,7 @@ describe("an action toast's lifetime", () => {
 
   it("keeps a longer setting", () => {
     configureNotifications({ durationMs: 12000 });
-    const id = notify({ message: "removed", action: undo });
+    const id = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(ACTION_TTL_MIN + 1);
     expect(shown(id)).toBe(true);
     vi.advanceTimersByTime(12000 - ACTION_TTL_MIN);
@@ -45,7 +46,7 @@ describe("an action toast's lifetime", () => {
 
   it("never dismisses when the reader chose never", () => {
     configureNotifications({ durationMs: 0 });
-    const id = notify({ message: "removed", action: undo });
+    const id = notify({ message: raw("removed"), action: undo });
     vi.advanceTimersByTime(60000);
     expect(shown(id)).toBe(true);
   });

frontend/src/lib/notifications.coalesce.dom.test.ts

@@ -0,0 +1,37 @@
+// @vitest-environment jsdom
+//
+// A burst of the same notice is one entry with a count (×N), not a pile of copies. The texts are
+// objects now (what to say, built afresh by every msg() call), so "the same" is the same key and
+// values, never the same object: a compare by reference would let every repeat stack.
+import { afterEach, describe, expect, it } from "vitest";
+import { clearAll, getNotifications, msg, notify, raw } from "./notifications";
+
+afterEach(() => clearAll());
+
+describe("coalescing a repeated notice", () => {
+  it("folds the same key and values into one entry, counted", () => {
+    notify({
+      level: "error",
+      title: msg("errors.title"),
+      message: msg("errors.reason.unreachable"),
+    });
+    notify({
+      level: "error",
+      title: msg("errors.title"),
+      message: msg("errors.reason.unreachable"),
+    });
+    expect(getNotifications().map((n) => n.repeat)).toEqual([2]);
+  });
+
+  it("folds the same server refusal too", () => {
+    notify({ level: "error", message: { detail: { code: "not_found", reason: "view" } } });
+    notify({ level: "error", message: { detail: { code: "not_found", reason: "view" } } });
+    expect(getNotifications().map((n) => n.repeat)).toEqual([2]);
+  });
+
+  it("keeps two notices apart when only a value differs", () => {
+    notify({ message: msg("channels.notify.hidden", { name: raw("One") }) });
+    notify({ message: msg("channels.notify.hidden", { name: raw("Two") }) });
+    expect(getNotifications().map((n) => n.repeat)).toEqual([1, 1]);
+  });
+});

frontend/src/lib/notifications.ts

@@ -2,9 +2,61 @@
 // the Notification Center shows (info events, actions awaiting interaction, and app
 // errors). History is persisted to localStorage so it survives reloads; action
 // callbacks are live-only and dropped on reload.
+import type { TFunction } from "i18next";
+import i18n from "../i18n";
+import { localizeDetail } from "./api/refusalText";
+import { formatBytes, formatNumber } from "./format";
 import { LS, onLocalDataClaimed, readAccount, readAccountMerged, writeAccount } from "./storage";
 import { log, type Level } from "./log";
 
+// What a notice SAYS, kept as what to say rather than the said text: a key and its values, said in
+// the reader's language each time it is shown. The text a caller translated at raise time was kept
+// in the history, so a language switch left every notice in the language it was raised in. `raw` is
+// text kept as it was fetched (a video's title, a name — a Plex title in the language it was fetched
+// in, since the card holds only that one); `detail` is a server refusal, localized at display like
+// the key. `notify` takes nothing else, and tsc refuses a plain string as a value (a name goes in as
+// `raw`, a translated word as its own `msg`). What tsc cannot see — `msg(t(…))`, `raw(t(…))`,
+// `{ detail: t(…) }`, or a `raw`/`msg` handed to a plain `t()` — notifText.contract.test refuses.
+// A value is formatted when shown too: `{ number }` / `{ bytes }` group digits the reader's way.
+export type NotifValue = number | NotifText | { number: number } | { bytes: number };
+export type NotifText =
+  | { key: string; values?: Readonly<Record<string, NotifValue>> }
+  | { raw: string }
+  | { detail: unknown };
+
+/** The notice text for `t(key, values)`, said when it is shown. */
+export const msg = (key: string, values?: Record<string, NotifValue>): NotifText =>
+  values ? { key, values } : { key };
+/** Text kept as it was fetched (a title, a name), shown as it is — never something `t()` said. */
+export const raw = (text: string): NotifText => ({ raw: text });
+
+/** A notice text in the language `t` speaks — the reader's, from a component's `useTranslation`. */
+export function sayNotif(text: NotifText, t: TFunction = i18n.t.bind(i18n)): string {
+  if ("raw" in text) return text.raw;
+  if ("detail" in text) return localizeDetail(text.detail);
+  if (!text.values) return t(text.key);
+  const values = Object.fromEntries(
+    Object.entries(text.values).map(([k, v]) => [k, sayValue(v, t)]),
+  );
+  return t(text.key, values);
+}
+
+function sayValue(v: NotifValue, t: TFunction): string | number {
+  if (typeof v !== "object") return v;
+  // In the language `t` speaks: a fixed one (the English log) names it, a component's follows i18n.
+  const lang = (t as { lng?: string }).lng ?? i18n.language;
+  if ("number" in v) return formatNumber(v.number, lang);
+  if ("bytes" in v) return formatBytes(v.bytes, lang);
+  return sayNotif(v, t);
+}
+
+const sameText = (a: NotifText | undefined, b: NotifText | undefined): boolean =>
+  JSON.stringify(a ?? null) === JSON.stringify(b ?? null);
+
+// A notice the history kept from before it said keys: its text, in the language it was raised in.
+const asText = (v: unknown): NotifText | undefined =>
+  typeof v === "string" ? raw(v) : (v as NotifText | undefined);
+
 // A notification's level in the client log: what the user was TOLD is part of the story a log tells.
 const LOG_LEVEL: Record<NotifLevel, Level> = {
   info: "INFO",
@@ -17,7 +69,8 @@ const LOG_LEVEL: Record<NotifLevel, Level> = {
 export type NotifLevel = "info" | "success" | "warning" | "error" | "fatal";
 
 interface NotifAction {
-  label: string;
+  // Said when shown, like the notice's text: a language switch must not leave the button behind.
+  label: NotifText;
   onClick: () => void;
 }
 
@@ -56,8 +109,8 @@ export type NotifMeta =
 export interface Notification {
   id: number;
   level: NotifLevel;
-  title?: string;
-  message: string;
+  title?: NotifText;
+  message: NotifText;
   action?: NotifAction;
   // A second, lesser action beside it (a done download's "Open" after its "Copy link").
   secondaryAction?: NotifAction;
@@ -79,9 +132,9 @@ export interface Notification {
 }
 
 export interface NotifyInput {
-  message: string;
+  message: NotifText;
   level?: NotifLevel;
-  title?: string;
+  title?: NotifText;
   action?: NotifAction;
   secondaryAction?: NotifAction;
   meta?: NotifMeta;
@@ -175,17 +228,21 @@ let cachedUnread = 0;
 
 function load(): Notification[] {
   try {
-    const raw = readAccount<unknown>(HISTORY_KEY, []);
-    if (!Array.isArray(raw)) return [];
+    // The old key only until the new one exists: its rows carry forward, said text as `raw`.
+    const stored =
+      readAccount<unknown>(HISTORY_KEY, null) ?? readAccount<unknown>(LS.legacyNotifHistory, []);
+    if (!Array.isArray(stored)) return [];
     // Restored entries are history only. Mark them dismissed so they don't
     // resurrect as active toasts on reload — their auto-dismiss timers aren't
     // re-armed across a reload, so otherwise they'd stick forever. Also drop the
     // live `action` callback, which can't survive serialization.
-    return raw.map(
+    return stored.map(
       (n) =>
         ({
           repeat: 1,
           ...(n as object),
+          title: asText((n as { title?: unknown }).title),
+          message: asText((n as { message?: unknown }).message) ?? raw(""),
           action: undefined,
           secondaryAction: undefined,
           dismissed: true,
@@ -261,9 +318,12 @@ const COALESCE_WINDOW_MS = 5000;
 export function notify(input: NotifyInput): number {
   const requiresInteraction = input.requiresInteraction ?? false;
   const level = input.level ?? "info";
-  log.at(LOG_LEVEL[level], "ui.notify", input.message, {
+  // In English, whatever the reader's language (a server refusal aside: it says itself in the
+  // reader's), so one log reads the same for every reader.
+  const en = i18n.getFixedT("en");
+  log.at(LOG_LEVEL[level], "ui.notify", sayNotif(input.message, en), {
     level,
-    ...(input.title ? { title: input.title } : {}),
+    ...(input.title ? { title: sayNotif(input.title, en) } : {}),
     ...(input.meta ? { kind: input.meta.kind } : {}),
   });
   const now = Date.now();
@@ -294,8 +354,8 @@ export function notify(input: NotifyInput): number {
         !n.action &&
         now - n.ts <= COALESCE_WINDOW_MS &&
         n.level === level &&
-        (n.title ?? "") === (input.title ?? "") &&
-        n.message === input.message,
+        sameText(n.title, input.title) &&
+        sameText(n.message, input.message),
     );
     if (prior) {
       // Re-surface the existing toast (undismiss + unread) and re-arm its auto-dismiss timer.

frontend/src/lib/playlistName.ts

@@ -1,7 +1,13 @@
 import type { TFunction } from "i18next";
+import { msg, raw, type NotifText } from "./notifications";
 
 /** Watch later is a built-in playlist whose stored `name` is not translatable — show the localized
  * label instead. Was hand-inlined in Playlists, PlaylistsRail and AddToPlaylist; one copy now. */
 export function playlistName(p: { kind: string; name: string }, t: TFunction): string {
   return p.kind === "watch_later" ? t("playlists.watchLater") : p.name;
 }
+
+/** The same name in a notice, said in the reader's language when it is shown. */
+export function playlistNameText(p: { kind: string; name: string }): NotifText {
+  return p.kind === "watch_later" ? msg("playlists.watchLater") : raw(p.name);
+}

frontend/src/lib/plexDetail.ts

@@ -3,6 +3,7 @@ import { REDUCED_MOTION, useMediaQuery } from "./useMediaQuery";
 import { usePref, useSavePref } from "./usePref";
 import type { TFunction } from "i18next";
 import type { PlexCard, PlexTmdb } from "./api";
+import { msg, raw, sayNotif, type NotifText } from "./notifications";
 
 // The non-component half of the shared Plex "detail page" UI (see plexDetailUi): the per-user display
 // prefs, the TMDB backdrop URL, the crossfading art backdrop hook and the episode label. Split out so
@@ -241,9 +242,17 @@ export function seasonTitle(
   se: { title?: string | null; season_number?: number | null },
   t: TFunction,
 ): string {
+  return sayNotif(seasonTitleText(se), t);
+}
+
+/** The season's name as a notice keeps it: said in the reader's language each time it is shown. */
+export function seasonTitleText(se: {
+  title?: string | null;
+  season_number?: number | null;
+}): NotifText {
   const n = se.season_number;
-  if (se.title && !GENERIC_SEASON.test(se.title.trim())) return se.title;
-  if (n === 0) return t("plex.specials");
-  if (n != null) return t("plex.seasonTitle", { n });
-  return se.title || t("plex.playlist.seasonUnknown");
+  if (se.title && !GENERIC_SEASON.test(se.title.trim())) return raw(se.title);
+  if (n === 0) return msg("plex.specials");
+  if (n != null) return msg("plex.seasonTitle", { n });
+  return se.title ? raw(se.title) : msg("plex.playlist.seasonUnknown");
 }

frontend/src/lib/plexWatch.ts

@@ -1,6 +1,6 @@
-import type { TFunction } from "i18next";
 import { api, type PlexCard } from "./api";
 import { notifyActionError } from "./actionErrors";
+import { msg } from "./notifications";
 
 // Persist a watch-state toggle from any Plex surface: flip via the caller's `optimistic` cache
 // updater, call the API, surface a failure (the click used to look dead on 403/404/429), then
@@ -12,7 +12,6 @@ import { notifyActionError } from "./actionErrors";
 // (react-query keeps the same `data`), or a cache whose refetch lands later than the click's answer.
 export async function toggleWatchState(
   card: PlexCard,
-  t: TFunction,
   handlers: { optimistic: (next: string) => void; resync: () => void; revert?: () => void },
 ) {
   const next = card.status === "watched" ? "new" : "watched";
@@ -21,7 +20,7 @@ export async function toggleWatchState(
     await api.plexSetState(card.id, next);
   } catch (e) {
     handlers.revert?.();
-    notifyActionError(e, t("plex.watchedFailed"));
+    notifyActionError(e, msg("plex.watchedFailed"));
   }
   handlers.resync();
 }

frontend/src/lib/queryClient.dom.test.ts

@@ -5,16 +5,18 @@
 // silence on a 403/404/429 or a lost connection — 34 of them.
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 
-vi.mock("./notifications", () => ({ notify: vi.fn(() => 0) }));
+vi.mock("./notifications", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("./notifications")>()),
+  notify: vi.fn(() => 0),
+}));
 vi.mock("./errorDialog", () => ({ reportError: vi.fn() }));
 
 import { MutationObserver, type MutationObserverOptions } from "@tanstack/react-query";
 import { createQueryClient } from "./queryClient";
 import { HttpError, req } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, raw } from "./notifications";
 import { reportError } from "./errorDialog";
 import { notifyActionError } from "./actionErrors";
-import i18n from "../i18n";
 
 const notifyMock = vi.mocked(notify);
 beforeEach(() => {
@@ -39,7 +41,7 @@ describe("a failed mutation", () => {
       meta: { failTitle: TITLE },
     });
     expect(notifyMock.mock.calls).toEqual([
-      [{ level: "error", title: i18n.t(TITLE), message: i18n.t("errors.notFound.generic") }],
+      [{ level: "error", title: msg(TITLE), message: msg("errors.notFound.generic") }],
     ]);
   });
 
@@ -47,8 +49,8 @@ describe("a failed mutation", () => {
     await fail({ mutationFn: () => Promise.reject(new HttpError(429, "slow down")) });
     expect(notifyMock).toHaveBeenCalledWith({
       level: "error",
-      title: i18n.t("errors.title"),
-      message: i18n.t("errors.reason.rateLimited"),
+      title: msg("errors.title"),
+      message: msg("errors.reason.rateLimited"),
     });
   });
 
@@ -58,7 +60,7 @@ describe("a failed mutation", () => {
       meta: { failTitle: TITLE },
     });
     expect(notifyMock).toHaveBeenCalledWith(
-      expect.objectContaining({ message: i18n.t("errors.reason.unreachable") }),
+      expect.objectContaining({ message: msg("errors.reason.unreachable") }),
     );
   });
 
@@ -66,9 +68,9 @@ describe("a failed mutation", () => {
     await fail({
       mutationFn: () => Promise.reject(new HttpError(404, "gone")),
       meta: { failTitle: TITLE },
-      onError: (e) => notifyActionError(e, "OWN TITLE"),
+      onError: (e) => notifyActionError(e, raw("OWN TITLE")),
     });
-    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual(["OWN TITLE"]);
+    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([raw("OWN TITLE")]);
   });
 
   it("is still reported when the mutation's onError only rolls back", async () => {
@@ -79,7 +81,7 @@ describe("a failed mutation", () => {
       onError: rollback,
     });
     expect(rollback).toHaveBeenCalled();
-    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([i18n.t(TITLE)]);
+    expect(notifyMock.mock.calls.map(([n]) => n.title)).toEqual([msg(TITLE)]);
   });
 
   it("gets no toast when the page shows the failure itself", async () => {

frontend/src/lib/queryClient.ts

@@ -1,7 +1,7 @@
 import { MutationCache, QueryCache, QueryClient } from "@tanstack/react-query";
-import i18n from "../i18n";
 import { notifyActionError } from "./actionErrors";
 import { log } from "./log";
+import { msg } from "./notifications";
 
 /** A failed query or mutation, for the client log. Only the key's HEAD (the resource, `"videos"`):
  *  the rest of a key is filter state, which the base level does not keep. The status is what
@@ -42,7 +42,7 @@ type FailMeta = { failTitle?: string; errorShownInline?: boolean } | undefined;
  */
 function reportMutationFailure(err: unknown, meta: FailMeta): void {
   if (meta?.errorShownInline) return;
-  setTimeout(() => notifyActionError(err, i18n.t(meta?.failTitle ?? "errors.title")), 0);
+  setTimeout(() => notifyActionError(err, msg(meta?.failTitle ?? "errors.title")), 0);
 }
 
 export function createQueryClient(): QueryClient {

frontend/src/lib/storage.ts

@@ -100,7 +100,12 @@ const KEYS = {
   // flag). A YT.Player instance is created per video and starts at full volume, so without this
   // every next video is loud again (same idea as plexPlayerPrefs).
   ytPlayerPrefs: { key: "siftlode.ytPlayerPrefs", kind: "device" },
-  notifHistory: { key: "siftlode.notifications", kind: "cache" },
+  // The notice history: what each notice says (lib/notifications NotifText), not the said text.
+  notifHistory: { key: "siftlode.notifHistory", kind: "cache" },
+  // DEPRECATED — the history as said text, which a build from before the change still reads (and
+  // renders as text: an object there crashed its Notifications page after a rollback). Read once while
+  // `notifHistory` does not exist yet, then inert. Do not write.
+  legacyNotifHistory: { key: "siftlode.notifications", kind: "cache" },
   notifSettings: { key: "siftlode.notifSettings", kind: "pref" },
   onboardingDismissed: { key: "siftlode.onboarding.dismissed", kind: "pref" },
   seenVersion: { key: "siftlode.seenVersion", kind: "pref" },

frontend/src/lib/useAccountSwitchNotice.dom.test.ts

@@ -28,6 +28,7 @@ vi.mock("./entryUrl", async (importOriginal) => {
   return { ...actual, accountSwitchNotice: () => notice() };
 });
 const { useAccountSwitchNotice } = await import("./useAccountSwitchNotice");
+const { msg, raw } = await import("./notifications");
 
 afterEach(() => {
   notifyMock.mockClear();
@@ -39,7 +40,7 @@ describe("the shell's word on a switch of account", () => {
     notice.mockReturnValue({
       level: "info",
       key: "header.account.switchRequested",
-      values: { email: "b@example.com" },
+      values: { email: raw("b@example.com") },
     });
     const { rerender } = renderHook(({ signedIn }) => useAccountSwitchNotice(signedIn), {
       initialProps: { signedIn: false },
@@ -53,7 +54,7 @@ describe("the shell's word on a switch of account", () => {
     expect(notifyMock).toHaveBeenCalledTimes(1);
     expect(notifyMock).toHaveBeenCalledWith({
       level: "info",
-      message: 'header.account.switchRequested {"email":"b@example.com"}',
+      message: msg("header.account.switchRequested", { email: raw("b@example.com") }),
     });
   });
 

frontend/src/lib/useAccountSwitchNotice.ts

@@ -1,7 +1,7 @@
 import { useEffect, useRef } from "react";
 import { useTranslation } from "react-i18next";
 import { accountSwitchNotice } from "./entryUrl";
-import { notify } from "./notifications";
+import { msg, notify } from "./notifications";
 
 /** Say, once per load, what the entry URL tells the account signed in here about a switch of
  * account (`accountSwitchNotice`): a sign-in as someone else the server refused, or a tab that
@@ -14,6 +14,6 @@ export function useAccountSwitchNotice(signedIn: boolean): void {
     if (!signedIn || said.current) return;
     said.current = true;
     const notice = accountSwitchNotice();
-    if (notice) notify({ level: notice.level, message: t(notice.key, notice.values) });
+    if (notice) notify({ level: notice.level, message: msg(notice.key, notice.values) });
   }, [signedIn, t]);
 }

frontend/src/lib/useChannelPriority.ts

@@ -1,8 +1,8 @@
 import { useCallback, useEffect, useRef } from "react";
 import { api } from "./api";
 import { notifyActionError } from "./actionErrors";
-import i18n from "../i18n";
 import { useLatest } from "./useLatest";
+import { msg } from "./notifications";
 
 /** The shared feed-priority flow used by both the channel manager and the channel detail page:
  *  an optimistic bump/set with a debounced server flush (~400ms after the last notch) so a
@@ -40,7 +40,7 @@ export function useChannelPriority(opts: {
         .catch((err: unknown) => {
           // Said here, once, for both callers: their `onError` only refetches, so a refused priority
           // used to just snap back — often after the stepper had already been let go.
-          notifyActionError(err, i18n.t("errors.writeFailed.channelPriority"));
+          notifyActionError(err, msg("errors.writeFailed.channelPriority"));
           optsRef.current.onError(channelId);
         });
     },

frontend/src/lib/useChannelTagActions.ts

@@ -1,8 +1,8 @@
 import { useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 import { api } from "./api";
 import { qk } from "./queryKeys";
 import { notifyActionError } from "./actionErrors";
+import { msg } from "./notifications";
 
 /** The shared channel-tag mutation flow used by both the channel manager and the channel detail
  *  page: optimistic attach/detach + a create-then-attach shortcut, with the cache-shape-specific
@@ -21,7 +21,6 @@ export function useChannelTagActions(opts: {
   onError: (channelId: string) => void;
 }) {
   const qc = useQueryClient();
-  const { t } = useTranslation();
 
   const toggleTag = (channelId: string, tagId: number, hasTag: boolean) => {
     opts.optimisticToggle(channelId, tagId, !hasTag);
@@ -31,7 +30,7 @@ export function useChannelTagActions(opts: {
     call
       .then(() => opts.onSuccess?.(channelId))
       .catch((err: unknown) => {
-        notifyActionError(err, t("channels.tags.updateFailed"));
+        notifyActionError(err, msg("channels.tags.updateFailed"));
         opts.onError(channelId);
       });
   };
@@ -45,7 +44,7 @@ export function useChannelTagActions(opts: {
         qc.invalidateQueries({ queryKey: qk.tags() });
         toggleTag(channelId, tag.id, false);
       })
-      .catch((err: unknown) => notifyActionError(err, t("channels.tags.createFailed")));
+      .catch((err: unknown) => notifyActionError(err, msg("channels.tags.createFailed")));
   };
 
   return { toggleTag, createAndAttachTag };

frontend/src/lib/usePref.saveFailure.dom.test.ts

@@ -17,7 +17,7 @@ vi.mock("./api", () => ({ api: { savePrefs, me: vi.fn() } }));
 vi.mock("./actionErrors", () => ({ notifyActionError }));
 
 import { usePref, useSavePref } from "./usePref";
-import i18n from "../i18n";
+import { msg } from "./notifications";
 
 afterEach(() => {
   savePrefs.mockReset();
@@ -34,7 +34,7 @@ describe("a refused preference save", () => {
     const { result } = renderHook(() => usePref<boolean>("hintsOn", true), { wrapper });
     act(() => result.current[1](false));
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(refusal, i18n.t("errors.writeFailed.prefs")),
+      expect(notifyActionError).toHaveBeenCalledWith(refusal, msg("errors.writeFailed.prefs")),
     );
     expect(result.current[0]).toBe(false); // the local value stays; the toast says it did not save
   });
@@ -45,7 +45,7 @@ describe("a refused preference save", () => {
     const { result } = renderHook(() => useSavePref(), { wrapper });
     act(() => result.current({ stripSources: { c1: false } }));
     await waitFor(() =>
-      expect(notifyActionError).toHaveBeenCalledWith(refusal, i18n.t("errors.writeFailed.prefs")),
+      expect(notifyActionError).toHaveBeenCalledWith(refusal, msg("errors.writeFailed.prefs")),
     );
   });
 });

frontend/src/lib/usePref.ts

@@ -6,13 +6,13 @@ import type { Me } from "./api/account";
 import { getAccountRaw, writeAccount } from "./storage";
 import { notifyActionError } from "./actionErrors";
 import { updateMeCache } from "./useMe";
-import i18n from "../i18n";
+import { msg } from "./notifications";
 
 // The local state + cache already show the new value, so a refused save is otherwise invisible until
 // the next load quietly puts the old one back. `req` reports none of 403/404/429 and only the
 // connection notice for a lost connection — say it.
 const reportPrefSaveFailure = (err: unknown) =>
-  notifyActionError(err, i18n.t("errors.writeFailed.prefs"));
+  notifyActionError(err, msg("errors.writeFailed.prefs"));
 
 // The ONE per-account + server preference hook. A preference (unlike an ephemeral filter) persists to
 // the account on the server (PUT /api/me/preferences, which MERGES the partial payload) and follows the

frontend/src/lib/useRail.ts

@@ -1,6 +1,5 @@
 import { useState } from "react";
 import { useQueryClient } from "@tanstack/react-query";
-import { useTranslation } from "react-i18next";
 import { api, type Me } from "./api";
 import { qk } from "./queryKeys";
 import { notifyActionError } from "./actionErrors";
@@ -15,6 +14,7 @@ import {
   type PanelId,
   type PanelLayout,
 } from "./panelLayout";
+import { msg } from "./notifications";
 
 // A side rail's own state: its group cards' layout and whether it is collapsed. Each rail reads it
 // here rather than being handed it, so the shell only places the rail.
@@ -24,7 +24,6 @@ import {
 // it. The server keeps the copy that follows the account, this browser a local one for an account
 // whose server copy has none.
 export function usePanelLayout(panel: PanelId): [PanelLayout, (next: PanelLayout) => void] {
-  const { t } = useTranslation();
   const qc = useQueryClient();
   const [layout, setState] = useState(() =>
     seedLayout(panel, qc.getQueryData<Me | null>(qk.me())?.preferences),
@@ -38,7 +37,7 @@ export function usePanelLayout(panel: PanelId): [PanelLayout, (next: PanelLayout
     }));
     api
       .savePrefs({ [PREF_KEY[panel]]: next })
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.prefs")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.prefs")));
   };
   return [layout, setLayout];
 }

frontend/src/lib/youtubeErrors.ts

@@ -1,16 +1,15 @@
 import { HttpError } from "./api";
 import { markReported } from "./api/core";
-import { notify } from "./notifications";
+import { msg, notify, type NotifText } from "./notifications";
 import { notifyActionError } from "./actionErrors";
-import i18n from "../i18n";
 
 // A YouTube-gated action (subscribe, sync, backfill, unsubscribe) that 403s means the user hasn't
 // granted the write scope — surface a "Connect" affordance instead of a vague failure. Pass
 // `onConnect` to offer the connect-wizard button (callers that have no wizard handle, e.g. the
-// channel page, just get the message). `fallbackMessage` is the already-translated non-403 error.
+// channel page, just get the message). `fallbackMessage` is what a non-403 error says.
 export function notifyYouTubeActionError(
   err: unknown,
-  fallbackMessage: string,
+  fallbackMessage: NotifText,
   onConnect?: () => void,
 ): void {
   const httpErr = err instanceof HttpError ? err : null;
@@ -18,10 +17,8 @@ export function notifyYouTubeActionError(
     // A 403 on a YouTube write action means the write scope isn't granted — offer to connect.
     notify({
       level: "error",
-      message: i18n.t("channels.notify.needYouTube"),
-      action: onConnect
-        ? { label: i18n.t("channels.notify.connect"), onClick: onConnect }
-        : undefined,
+      message: msg("channels.notify.needYouTube"),
+      action: onConnect ? { label: msg("channels.notify.connect"), onClick: onConnect } : undefined,
     });
     markReported(err);
     return;

frontend/src/modules/activity/ActivityAudit.tsx

@@ -8,7 +8,7 @@ import { notifyActionError } from "../../lib/actionErrors";
 import { sinceOf } from "../../lib/activityUrlState";
 import { auditActionLabel, auditText } from "../../lib/auditText";
 import { formatDateTimeSec } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { useHistoryList } from "../../lib/useHistoryList";
 import type { Shared } from "./ActivityRuns";
@@ -70,9 +70,9 @@ export default function ActivityAudit({
     onSuccess: (r) => {
       void qc.invalidateQueries({ queryKey: qk.adminAudit() });
       void qc.invalidateQueries({ queryKey: qk.adminAuditFacets() });
-      notify({ level: "success", message: t("audit.cleared", { count: r.cleared }) });
+      notify({ level: "success", message: msg("audit.cleared", { count: r.cleared }) });
     },
-    onError: (e) => notifyActionError(e, t("audit.clearFailed")),
+    onError: (e) => notifyActionError(e, msg("audit.clearFailed")),
   });
   const onClear = async () => {
     if (

frontend/src/modules/activity/AdminLogs.tsx

@@ -15,7 +15,7 @@ import { nextPageOnClick } from "../../lib/nextPage";
 import { LEVEL_GROUPS, type LevelGroup } from "../../lib/log";
 import { sinceOf } from "../../lib/activityUrlState";
 import { logsParamsToState, logsParamUpdates, type LogsUrlState } from "../../lib/logsUrlState";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { useUrlMirror } from "../../lib/useUrlMirror";
 import { HistoryFrame } from "./HistoryList";
@@ -187,8 +187,8 @@ export default function AdminLogs({
     const ok = await copyText(text);
     notify(
       ok
-        ? { level: "success", message: t("adminLogs.copied", { count: rows.length }) }
-        : { level: "error", message: t("adminLogs.copyFailed") },
+        ? { level: "success", message: msg("adminLogs.copied", { count: rows.length }) }
+        : { level: "error", message: msg("adminLogs.copyFailed") },
     );
   };
 

frontend/src/modules/channels/ChannelDiscovery.tsx

@@ -11,7 +11,7 @@ import { hydrateSort, sortRows, type SortState } from "../../lib/columnSort";
 import { usePref } from "../../lib/usePref";
 import { useCardPager } from "../../lib/useCardPager";
 import { subsColumn } from "./channelColumns";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import Tooltip from "../../components/ui/Tooltip";
 import ChannelLink from "./ChannelLink";
@@ -70,13 +70,13 @@ export default function ChannelDiscovery({
       // callbacks are gone (see ChannelSubscribedMeta).
       notify({
         level: "success",
-        title: t("channels.discovery.subscribedTitle"),
-        message: t("channels.discovery.subscribedBody", { name }),
+        title: msg("channels.discovery.subscribedTitle"),
+        message: msg("channels.discovery.subscribedBody", { name: raw(name) }),
         meta: { kind: "channel-subscribed", channelId: c.id, channelName: name },
       });
     },
     onError: (err: unknown) =>
-      notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed"), onOpenWizard),
   });
 
   // Subscribing changes the user's real YouTube account and spends a little quota — confirm

frontend/src/modules/channels/Channels.tsx

@@ -18,7 +18,7 @@ import { Sparkles } from "lucide-react";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { LS, ownKey } from "../../lib/storage";
 import { buildChannelColumns, applySyncFilter, tagFilterChips } from "./channelColumns";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { Badge } from "../../components/ui/Badge";
 import { Button } from "../../components/ui/Button";
 import Tooltip from "../../components/ui/Tooltip";
@@ -168,9 +168,9 @@ export default function Channels() {
     (tagId: number, name: string) => {
       setFeedFilters({ ...feedFilters, tags: [tagId], channelIds: [] });
       setPage("feed");
-      notify({ level: "info", message: t("channels.notify.filteredByTag", { name }) });
+      notify({ level: "info", message: msg("channels.notify.filteredByTag", { name: raw(name) }) });
     },
-    [setFeedFilters, feedFilters, setPage, t],
+    [setFeedFilters, feedFilters, setPage],
   );
 
   const channelsQuery = useQuery({ queryKey: qk.channels(), queryFn: api.channels });
@@ -294,10 +294,10 @@ export default function Channels() {
       invalidate();
       notify({
         level: "success",
-        message: t("channels.notify.synced", { count: r.subscriptions ?? 0 }),
+        message: msg("channels.notify.synced", { count: r.subscriptions ?? 0 }),
       });
     },
-    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.syncFailed"), onOpenWizard),
+    onError: (e) => notifyYouTubeActionError(e, msg("channels.notify.syncFailed"), onOpenWizard),
   });
   const deepAll = useMutation({
     mutationFn: () => api.deepAll(true),
@@ -306,11 +306,11 @@ export default function Channels() {
       qc.invalidateQueries({ queryKey: qk.myStatus() });
       notify({
         level: "success",
-        message: t("channels.notify.fullHistoryRequested", { count: r.updated ?? 0 }),
+        message: msg("channels.notify.fullHistoryRequested", { count: r.updated ?? 0 }),
       });
     },
     onError: (e) =>
-      notifyYouTubeActionError(e, t("channels.notify.fullHistoryFailed"), onOpenWizard),
+      notifyYouTubeActionError(e, msg("channels.notify.fullHistoryFailed"), onOpenWizard),
   });
 
   // The tag-chip row is a controlled view over the Tags COLUMN filter (`filters.tags`, a string[] of
@@ -406,7 +406,10 @@ export default function Channels() {
     ((channelsQuery.data ?? []).find((c) => c.id === rowMenu.target!.id) ?? rowMenu.target);
   const menuItems = menuRow
     ? channelActions.items(menuRow, {
-        pin: rowPin.item(pinChannel(menuRow.id), menuRow.title ?? t("channels.row.thisChannel")),
+        pin: rowPin.item(
+          pinChannel(menuRow.id),
+          menuRow.title == null ? msg("channels.row.thisChannel") : raw(menuRow.title),
+        ),
       })
     : [];
 

frontend/src/modules/channels/SyncStatus.tsx

@@ -12,6 +12,7 @@ import { Button } from "../../components/ui/Button";
 import { IconButton } from "../../components/ui/IconButton";
 import { Pressable } from "../../components/ui/Pressable";
 import { SURFACE } from "../../components/ui/surfaces";
+import { msg } from "../../lib/notifications";
 
 // Per-user status (not the global catalog): shows the number of videos available to *this*
 // user, how many of *their* channels are still being fetched, and how many lack full
@@ -64,7 +65,7 @@ export default function SyncStatus({
     onError: (e) =>
       notifyActionError(
         e,
-        t(data?.paused ? "errors.writeFailed.syncResume" : "errors.writeFailed.syncPause"),
+        msg(data?.paused ? "errors.writeFailed.syncResume" : "errors.writeFailed.syncPause"),
       ),
   });
 

frontend/src/modules/channels/WatchedChannels.dom.test.tsx

@@ -59,6 +59,7 @@ vi.mock("../../features/player/PlayerModal", () => ({
 import WatchedChannels from "./WatchedChannels";
 import { qk } from "../../lib/queryKeys";
 import { api, type Video, type WatchedChannel, type WatchedChannels as List } from "../../lib/api";
+import { msg, type NotifText } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -149,8 +150,10 @@ describe("WatchedChannels", () => {
     fireEvent.click(await screen.findByRole("button", { name: "channels.watched.dismiss" }));
     await waitFor(() => expect(h.notify).toHaveBeenCalled());
     expect(dismiss).toHaveBeenCalledWith("UC1");
-    const toast = h.notify.mock.calls[0]![0] as { action: { label: string; onClick: () => void } };
-    expect(toast.action.label).toBe("common.undo");
+    const toast = h.notify.mock.calls[0]![0] as {
+      action: { label: NotifText; onClick: () => void };
+    };
+    expect(toast.action.label).toEqual(msg("common.undo"));
     act(() => toast.action.onClick());
     await waitFor(() => expect(restore).toHaveBeenCalledWith("UC1"));
   });

frontend/src/modules/channels/WatchedVideosDialog.tsx

@@ -16,6 +16,7 @@ import { Pressable } from "../../components/ui/Pressable";
 import RemoteImage from "../../components/ui/RemoteImage";
 import Tooltip from "../../components/ui/Tooltip";
 import type { WatchedChannelActions } from "./useWatchedChannelActions";
+import { msg } from "../../lib/notifications";
 
 const PlayerModal = lazy(() => import("../../features/player/PlayerModal"));
 
@@ -67,7 +68,7 @@ export default function WatchedVideosDialog({
         );
         void qc.invalidateQueries({ queryKey: qk.feed() });
       })
-      .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
+      .catch((e: unknown) => notifyActionError(e, msg("errors.writeFailed.videoState")));
     return write;
   });
   const closePlayer = useStableCallback(() => setPlaying(null));

frontend/src/modules/channels/useChannelActions.dom.test.tsx

@@ -33,6 +33,7 @@ vi.mock("../../lib/useMe", () => ({ useMe: () => ({ role: h.role, can_write: h.c
 import { useChannelActions } from "./useChannelActions";
 import { api, type ManagedChannel, type Tag } from "../../lib/api";
 import type { ActionMenuItem } from "../../components/ui/ActionMenu";
+import { msg, type NotifText, raw } from "../../lib/notifications";
 
 afterEach(() => {
   cleanup();
@@ -195,14 +196,27 @@ describe("useChannelActions — hide and unsubscribe", () => {
     expect(h.confirm).not.toHaveBeenCalled();
     expect(upd).toHaveBeenCalledWith("UC1", { hidden: true });
     const toast = h.notify.mock.calls[0]![0] as {
-      message: string;
+      message: NotifText;
       action: { onClick: () => void };
     };
-    expect(toast.message).toBe("channels.notify.hidden");
+    expect(toast.message).toEqual(msg("channels.notify.hidden", { name: raw("Chan") }));
     act(() => toast.action.onClick());
     await waitFor(() => expect(upd).toHaveBeenCalledWith("UC1", { hidden: false }));
   });
 
+  it('names a channel with no title yet as "this channel" in the reader\'s language when shown', async () => {
+    vi.spyOn(api, "updateChannel").mockResolvedValue({} as never);
+    const { result } = mount();
+    act(() =>
+      result.current.items(ch({ title: null }), { pin }).find((i) => i.id === "hide")!.onSelect!(),
+    );
+    await waitFor(() => expect(h.notify).toHaveBeenCalled());
+    const toast = h.notify.mock.calls[0]![0] as { message: NotifText };
+    expect(toast.message).toEqual(
+      msg("channels.notify.hidden", { name: msg("channels.row.thisChannel") }),
+    );
+  });
+
   it("unsubscribes only after the danger confirm says yes", async () => {
     const unsub = vi.spyOn(api, "unsubscribeChannel").mockResolvedValue({} as never);
     const { result } = mount();

frontend/src/modules/channels/useChannelActions.tsx

@@ -7,7 +7,7 @@ import { api, type ManagedChannel, type Tag } from "../../lib/api";
 import { priorityChoices } from "../../lib/channelOrder";
 import { compareText } from "../../lib/collate";
 import { channelYouTubeUrl } from "../../lib/format";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { useMe } from "../../lib/useMe";
 import { useConfirm } from "../../components/ui/confirmContext";
@@ -46,7 +46,9 @@ export function useChannelActions({
   const me = useMe();
   const isAdmin = me.role === "admin";
   const copy = useCopyItems();
-  const nameOf = (c: ManagedChannel) => c.title ?? t("channels.row.thisChannel");
+  // The notice says it when shown: a channel with no title yet is "this channel" in the reader's language.
+  const nameOf = (c: ManagedChannel) =>
+    c.title == null ? msg("channels.row.thisChannel") : raw(c.title);
 
   const refresh = () => {
     qc.invalidateQueries({ queryKey: qk.channels() });
@@ -70,9 +72,9 @@ export function useChannelActions({
       refresh();
       notify({
         level: "success",
-        message: t("channels.notify.hidden", { name: nameOf(c) }),
+        message: msg("channels.notify.hidden", { name: nameOf(c) }),
         action: {
-          label: t("common.undo"),
+          label: msg("common.undo"),
           onClick: () => patch.mutate({ id: c.id, body: { hidden: false } }),
         },
       });
@@ -82,19 +84,22 @@ export function useChannelActions({
     mutationFn: (c: ManagedChannel) => api.unsubscribeChannel(c.id),
     onSuccess: (_d, c) => {
       invalidateSubscription(qc, c.id);
-      notify({ level: "success", message: t("channels.notify.unsubscribed", { name: nameOf(c) }) });
+      notify({
+        level: "success",
+        message: msg("channels.notify.unsubscribed", { name: nameOf(c) }),
+      });
     },
     onError: (e) =>
-      notifyYouTubeActionError(e, t("channels.notify.unsubscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(e, msg("channels.notify.unsubscribeFailed"), onOpenWizard),
   });
   const resetBackfill = useMutation({
     mutationFn: (c: ManagedChannel) => api.resetChannelBackfill(c.id),
     onSuccess: (_d, c) => {
       qc.invalidateQueries({ queryKey: qk.channels() });
       qc.invalidateQueries({ queryKey: qk.myStatus() });
-      notify({ level: "success", message: t("channels.notify.resetDone", { name: nameOf(c) }) });
+      notify({ level: "success", message: msg("channels.notify.resetDone", { name: nameOf(c) }) });
     },
-    onError: (e) => notifyYouTubeActionError(e, t("channels.notify.resetFailed"), onOpenWizard),
+    onError: (e) => notifyYouTubeActionError(e, msg("channels.notify.resetFailed"), onOpenWizard),
   });
 
   async function onUnsubscribe(c: ManagedChannel) {

frontend/src/modules/channels/useWatchedChannelActions.confirm.dom.test.tsx

@@ -0,0 +1,39 @@
+// @vitest-environment jsdom
+//
+// Subscribing changes the reader's real YouTube account, so the confirm names the channel it
+// subscribes to — in both languages, through the real i18n. A notice's value (`raw`, `msg`) is said
+// only by sayNotif: handed to a plain `t()` it reads "[object Object]".
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { act, cleanup, renderHook } from "@testing-library/react";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import type { ReactNode } from "react";
+import i18n from "../../i18n";
+
+const h = vi.hoisted(() => ({ confirm: vi.fn(async (_o: { message: string }) => false) }));
+vi.mock("../../components/ui/confirmContext", () => ({ useConfirm: () => h.confirm }));
+
+import { useWatchedChannelActions } from "./useWatchedChannelActions";
+import type { WatchedChannel } from "../../lib/api";
+
+afterEach(async () => {
+  cleanup();
+  h.confirm.mockClear();
+  await i18n.changeLanguage("en");
+});
+
+const channel = { id: "UC1", title: "Kurzgesagt" } as WatchedChannel;
+
+const wrapper = ({ children }: { children: ReactNode }) => (
+  <QueryClientProvider client={new QueryClient()}>{children}</QueryClientProvider>
+);
+
+describe("the subscribe confirm", () => {
+  it.each(["en", "hu"])("names the channel (%s)", async (lng) => {
+    await i18n.changeLanguage(lng);
+    const { result } = renderHook(() => useWatchedChannelActions(() => {}), { wrapper });
+    await act(() => result.current.onSubscribe(channel));
+    const said = h.confirm.mock.lastCall![0].message;
+    expect(said).toContain("Kurzgesagt");
+    expect(said).not.toContain("[object Object]");
+  });
+});

frontend/src/modules/channels/useWatchedChannelActions.ts

@@ -3,7 +3,7 @@ import { useMutation, useQueryClient } from "@tanstack/react-query";
 import { qk } from "../../lib/queryKeys";
 import { invalidateSubscription } from "../../lib/subscriptionCache";
 import { api, type WatchedChannel } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { useConfirm } from "../../components/ui/confirmContext";
 
@@ -21,13 +21,13 @@ export function useWatchedChannelActions(onOpenWizard: () => void) {
       invalidateSubscription(qc, c.id);
       notify({
         level: "success",
-        title: t("channels.discovery.subscribedTitle"),
-        message: t("channels.discovery.subscribedBody", { name: nameOf(c) }),
+        title: msg("channels.discovery.subscribedTitle"),
+        message: msg("channels.discovery.subscribedBody", { name: raw(nameOf(c)) }),
         meta: { kind: "channel-subscribed", channelId: c.id, channelName: nameOf(c) },
       });
     },
     onError: (err: unknown) =>
-      notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed"), onOpenWizard),
+      notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed"), onOpenWizard),
   });
   const restore = useMutation({
     mutationFn: (c: WatchedChannel) => api.restoreWatchedChannel(c.id),
@@ -43,8 +43,8 @@ export function useWatchedChannelActions(onOpenWizard: () => void) {
       void qc.invalidateQueries({ queryKey: qk.watchedChannels() });
       notify({
         level: "success",
-        message: t("channels.watched.dismissed", { name: nameOf(c) }),
-        action: { label: t("common.undo"), onClick: () => restore.mutate(c) },
+        message: msg("channels.watched.dismissed", { name: raw(nameOf(c)) }),
+        action: { label: msg("common.undo"), onClick: () => restore.mutate(c) },
       });
     },
   });

frontend/src/modules/config/ConfigPanel.tsx

@@ -4,7 +4,7 @@ import { useTranslation } from "react-i18next";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { Plug, RotateCcw, Send } from "lucide-react";
 import { api, type ConfigItem, type PlexTestResult } from "../../lib/api";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import Tooltip from "../../components/ui/Tooltip";
 import InlineNotice from "../../components/ui/InlineNotice";
 import { useMe } from "../../lib/useMe";
@@ -130,7 +130,7 @@ export default function ConfigPanel() {
       setTimeout(() => setSaveState((s) => (s === "saved" ? "idle" : s)), 2500);
     } catch (e) {
       setSaveState("error");
-      notifyActionError(e, t("config.saveFailed"));
+      notifyActionError(e, msg("config.saveFailed"));
     }
   }
 
@@ -142,8 +142,9 @@ export default function ConfigPanel() {
 
   const testEmail = useMutation({
     mutationFn: () => api.testEmail(),
-    onSuccess: (r) => notify({ level: "success", message: t("config.testSent", { to: r.to }) }),
-    onError: (e) => notifyActionError(e, t("config.testFailed")),
+    onSuccess: (r) =>
+      notify({ level: "success", message: msg("config.testSent", { to: raw(r.to) }) }),
+    onError: (e) => notifyActionError(e, msg("config.testFailed")),
   });
 
   // Plex "Test connection": verifies the server URL + token and returns the library sections,
@@ -154,19 +155,19 @@ export default function ConfigPanel() {
     mutationFn: () => api.testPlex(),
     onSuccess: (r) => {
       setPlexResult(r);
-      notify({ level: "success", message: t("config.plexTestOk", { name: r.server_name }) });
+      notify({ level: "success", message: msg("config.plexTestOk", { name: raw(r.server_name) }) });
     },
     onError: (e) => {
       setPlexResult(null);
-      notifyActionError(e, t("config.plexTestFailed"));
+      notifyActionError(e, msg("config.plexTestFailed"));
     },
   });
   // Bug reports' "Test connection": the repository answers, takes issues, is private.
   const testIssues = useMutation({
     mutationFn: () => api.testIssues(),
     onSuccess: (r) =>
-      notify({ level: "success", message: t("config.issuesTestOk", { repo: r.repo }) }),
-    onError: (e) => notifyActionError(e, t("config.issuesTestFailed")),
+      notify({ level: "success", message: msg("config.issuesTestOk", { repo: raw(r.repo) }) }),
+    onError: (e) => notifyActionError(e, msg("config.issuesTestFailed")),
   });
 
   const plexLibs = (draft["plex_libraries"] ?? "")

frontend/src/modules/feed/ChannelPage.tsx

@@ -42,7 +42,7 @@ import {
 } from "../../lib/channelPageUrlState";
 import { LS } from "../../lib/storage";
 import { useConfirm } from "../../components/ui/confirmContext";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { notifyYouTubeActionError } from "../../lib/youtubeErrors";
 import { notifyActionError } from "../../lib/actionErrors";
 import {
@@ -152,11 +152,11 @@ export default function ChannelPage({
           })
           // Both the automatic first-visit explore and "load more" used to fail in silence: an empty
           // channel page that looked like a channel with no videos.
-          .catch((err: unknown) => notifyActionError(err, t("errors.writeFailed.exploreChannel")))
+          .catch((err: unknown) => notifyActionError(err, msg("errors.writeFailed.exploreChannel")))
           .finally(() => setExploring(false))
       );
     },
-    [channelId, qc, t],
+    [channelId, qc],
   );
 
   // First visit of an un-subscribed channel → ingest its recent uploads. Skipped when videos are
@@ -201,16 +201,16 @@ export default function ChannelPage({
     mutationFn: () => api.subscribeChannel(channelId),
     onSuccess: () => {
       invalidateSubscription(qc, channelId);
-      notify({ level: "info", message: t("channel.subscribed", { name: ch?.title ?? "" }) });
+      notify({ level: "info", message: msg("channel.subscribed", { name: raw(ch?.title ?? "") }) });
     },
     // A 403 (missing write scope) otherwise fails silently on the channel page (no wizard handle
     // here, so no Connect button — but the user at least sees why it didn't work).
-    onError: (err) => notifyYouTubeActionError(err, t("channels.discovery.subscribeFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channels.discovery.subscribeFailed")),
   });
   const unsubscribe = useMutation({
     mutationFn: () => api.unsubscribeChannel(channelId),
     onSuccess: () => invalidateSubscription(qc, channelId),
-    onError: (err) => notifyYouTubeActionError(err, t("channels.notify.unsubscribeFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channels.notify.unsubscribeFailed")),
   });
   // "Get full history": the catalog only holds the recent-backfill/RSS subset of a channel's
   // uploads (video_count is YouTube's raw total), so flipping deep_requested queues the full
@@ -222,9 +222,9 @@ export default function ChannelPage({
       qc.invalidateQueries({ queryKey: qk.feed() });
       qc.invalidateQueries({ queryKey: qk.channels() });
       qc.invalidateQueries({ queryKey: qk.myStatus() });
-      notify({ level: "info", message: t("channel.fullHistoryQueued") });
+      notify({ level: "info", message: msg("channel.fullHistoryQueued") });
     },
-    onError: (err) => notifyYouTubeActionError(err, t("channel.fullHistoryFailed")),
+    onError: (err) => notifyYouTubeActionError(err, msg("channel.fullHistoryFailed")),
   });
 
   // Feed priority, editable here with the same stepper + debounced-flush the manager uses (shared

frontend/src/modules/feed/Feed.tsx

@@ -31,7 +31,6 @@ import {
   type Video,
   type VideoStatus,
 } from "../../lib/api";
-import i18n from "../../i18n";
 import { notifyActionError } from "../../lib/actionErrors";
 import { announceVideoState, type NoticeVideo } from "../../features/video/stateNotice";
 import {
@@ -39,7 +38,7 @@ import {
   writeVideoState,
   writeWatchLater,
 } from "../../features/video/videoWrites";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { useMe } from "../../lib/useMe";
 import { YT_COUNTS } from "../../lib/ytSearchUrlState";
 import { useNavigation, useNavigationActions } from "../../features/navigation/navigationContext";
@@ -419,7 +418,7 @@ export default function Feed({
           // Server rejected the change — drop the optimistic override so the card
           // reverts to the real (unchanged) state instead of staying phantom-hidden, and say so:
           // a card that silently snaps back reads as a misclick.
-          notifyActionError(e, i18n.t("errors.writeFailed.videoState"));
+          notifyActionError(e, msg("errors.writeFailed.videoState"));
           setOverrides((o) => withoutWrite(o, id, seq));
         });
       return write;
@@ -447,7 +446,7 @@ export default function Feed({
           qc.invalidateQueries({ queryKey: qk.feed(), refetchType: "none" });
         })
         .catch((e: unknown) => {
-          notifyActionError(e, i18n.t("errors.writeFailed.videoReset"));
+          notifyActionError(e, msg("errors.writeFailed.videoReset"));
           setOverrides((o) => withoutWrite(o, id, seq));
           if (resets.current.get(id) !== seq) return;
           resets.current.delete(id);
@@ -471,9 +470,7 @@ export default function Feed({
         .catch((e: unknown) => {
           notifyActionError(
             e,
-            i18n.t(
-              saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove",
-            ),
+            msg(saved ? "errors.writeFailed.watchLaterAdd" : "errors.writeFailed.watchLaterRemove"),
           );
           setSavedOverrides((o) => withoutWrite(o, id, seq));
         });
@@ -619,11 +616,9 @@ export default function Feed({
                   const ids = ytItems.map((v) => v.id);
                   api
                     .clearSearch(ids)
-                    .then((r) =>
-                      notify({ message: i18n.t("feed.yt.cleared", { count: r.removed }) }),
-                    )
+                    .then((r) => notify({ message: msg("feed.yt.cleared", { count: r.removed }) }))
                     .catch((e: unknown) =>
-                      notifyActionError(e, i18n.t("errors.writeFailed.clearSearch")),
+                      notifyActionError(e, msg("errors.writeFailed.clearSearch")),
                     );
                   setFilters({ ...filters, librarySource: "organic", sort: FEED_DEFAULT_SORT });
                   onExitYtSearch();

frontend/src/modules/files/Files.menu.dom.test.tsx

@@ -116,6 +116,7 @@ vi.mock("../../components/ui/PageShell", async (importOriginal) => ({
 }));
 
 import Files from "./Files";
+import { msg } from "../../lib/notifications";
 import { FILES_LIST_CAP, type QueueJob } from "../../lib/api";
 import { noteQueue, resetQueueWatch, useFinished } from "../../lib/downloadQueue";
 
@@ -589,10 +590,13 @@ describe("Files · a library past the list's cap", { timeout: 30_000 }, () => {
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith({
         level: "info",
-        message: "files.arrival.notListed",
+        message: msg("files.arrival.notListed"),
       }),
     );
-    expect(mocks.notify).not.toHaveBeenCalledWith({ level: "info", message: "files.arrival.gone" });
+    expect(mocks.notify).not.toHaveBeenCalledWith({
+      level: "info",
+      message: msg("files.arrival.gone"),
+    });
   });
 
   it("an arrival's cleared search is asked of the server at once, not after the typing pause", () => {
@@ -805,7 +809,7 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "warning", message: "files.linkedGone" }),
+        expect.objectContaining({ level: "warning", message: msg("files.linkedGone") }),
       ),
     );
     expect(screen.queryByRole("dialog")).toBeNull();
@@ -822,11 +826,11 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "info", message: "files.linkedNotListed" }),
+        expect.objectContaining({ level: "info", message: msg("files.linkedNotListed") }),
       ),
     );
     expect(mocks.notify).not.toHaveBeenCalledWith(
-      expect.objectContaining({ message: "files.linkedGone" }),
+      expect.objectContaining({ message: msg("files.linkedGone") }),
     );
     expect(here().get("fview")).toBe("9999");
   }, 30_000); // a full page of FILES_LIST_CAP rows
@@ -839,11 +843,11 @@ describe("Files · a file the address names", () => {
     mount();
     await waitFor(() =>
       expect(mocks.notify).toHaveBeenCalledWith(
-        expect.objectContaining({ level: "info", message: "files.linkedNotListed" }),
+        expect.objectContaining({ level: "info", message: msg("files.linkedNotListed") }),
       ),
     );
     expect(mocks.notify).not.toHaveBeenCalledWith(
-      expect.objectContaining({ message: "files.linkedGone" }),
+      expect.objectContaining({ message: msg("files.linkedGone") }),
     );
     expect(here().get("fview")).toBe("9999");
   }, 30_000); // a full page of FILES_LIST_CAP rows
@@ -1344,7 +1348,10 @@ describe("Files · when what it needs is missing", () => {
     mocks.folders = [YT];
     mount(ALL_FILES, vi.fn(), "", { focus: { id: 9, token: 1 } });
     await waitFor(() =>
-      expect(mocks.notify).toHaveBeenCalledWith({ level: "info", message: "files.arrival.gone" }),
+      expect(mocks.notify).toHaveBeenCalledWith({
+        level: "info",
+        message: msg("files.arrival.gone"),
+      }),
     );
   });
 });

frontend/src/modules/files/Files.tsx

@@ -19,7 +19,7 @@ import {
 import { libraryRowActions, sharedRowActions } from "../../lib/downloadActions";
 import { formatBytes, formatDateTime, relativeTime } from "../../lib/format";
 import { focusNavItem } from "../../lib/listNav";
-import { notify } from "../../lib/notifications";
+import { msg, notify } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
 import { LS, ownKey } from "../../lib/storage";
 import { useCardPager } from "../../lib/useCardPager";
@@ -296,9 +296,9 @@ export default function Files() {
   const openLinked = useEffectEvent((file: LibraryFile | undefined) => {
     // Looked for in the list it was shown in: a cut one cannot tell (the newest files, or the first by
     // its sort or search), as the arrival decides it.
-    if (!file && cut) notify({ level: "info", message: t("files.linkedNotListed") });
+    if (!file && cut) notify({ level: "info", message: msg("files.linkedNotListed") });
     else if (!file) {
-      notify({ level: "warning", message: t("files.linkedGone") });
+      notify({ level: "warning", message: msg("files.linkedGone") });
       clearParams(FILES_VIEW_KEY, FILES_PLAY_KEY);
     } else if (linkedFile?.open === "play") play(file);
     else setViewing(file.id);
@@ -387,7 +387,10 @@ export default function Files() {
       consumeFocus(null);
       // Said, not swallowed. A list the cap cut cannot tell a deleted file from one beyond its end;
       // a whole list can: an old notice's file may have expired or been deleted since.
-      notify({ level: "info", message: t(cut ? "files.arrival.notListed" : "files.arrival.gone") });
+      notify({
+        level: "info",
+        message: msg(cut ? "files.arrival.notListed" : "files.arrival.gone"),
+      });
     }
   }, [here, missing, lookEverywhere, cut, viewKey, setView, consumeFocus, t]);
   const arrival = arrived && arrived.view === viewKey ? arrived : null;
@@ -434,7 +437,7 @@ export default function Files() {
       const dropped = e.dataTransfer.files;
       const first = dropped.item(0);
       if (first) setUpload({ file: first });
-      if (dropped.length > 1) notify({ level: "info", message: t("files.drop.oneAtATime") });
+      if (dropped.length > 1) notify({ level: "info", message: msg("files.drop.oneAtATime") });
     }
     setDragging(dragDepth.current > 0);
   });

frontend/src/modules/files/ShareDialog.tsx

@@ -5,7 +5,7 @@ import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { Check, Copy, Link2, Lock, Trash2, UserPlus, Eye } from "lucide-react";
 import Modal from "../../components/ui/Modal";
 import { useConfirm } from "../../components/ui/confirmContext";
-import { notify } from "../../lib/notifications";
+import { msg, notify, raw } from "../../lib/notifications";
 import { notifyActionError } from "../../lib/actionErrors";
 import { formatDate } from "../../lib/format";
 import { api, type DownloadJob, type ShareLink, type ShareRecipient } from "../../lib/api";
@@ -40,9 +40,12 @@ function UserShare({ job }: { job: DownloadJob }) {
   const share = useMutation({
     mutationFn: (email: string) => api.shareDownload(job.id, email),
     onSuccess: (r) => {
-      notify({ level: "success", message: t("downloads.share.done", { email: r.shared_with }) });
+      notify({
+        level: "success",
+        message: msg("downloads.share.done", { email: raw(r.shared_with) }),
+      });
     },
-    onError: (e) => notifyActionError(e, t("downloads.share.failed")),
+    onError: (e) => notifyActionError(e, msg("downloads.share.failed")),
   });
 
   return (

frontend/src/modules/files/UploadDialog.dom.test.tsx

@@ -45,6 +45,7 @@ vi.mock("../../lib/downloadQueue", () => ({
 
 import UploadDialog from "./UploadDialog";
 import { FilesActionsContext } from "./filesContext";
+import { msg, type NotifText } from "../../lib/notifications";
 
 const wrap = (
   onClose = vi.fn(),
@@ -101,7 +102,9 @@ describe("UploadDialog", () => {
     expect(passedFile).toBe(f);
     expect((opts as { displayName?: string }).displayName).toBe("My notes");
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
-    expect(h.notify.mock.calls[0]![0]).toMatchObject({ message: "downloads.upload.added" });
+    expect((h.notify.mock.calls[0]![0] as { message: NotifText }).message).toEqual(
+      msg("downloads.upload.added"),
+    );
     await waitFor(() => expect(onClose).toHaveBeenCalled());
   });
 
@@ -115,9 +118,9 @@ describe("UploadDialog", () => {
     });
     fireEvent.click(screen.getByText("downloads.upload.submit"));
     await waitFor(() => expect(h.notify).toHaveBeenCalledTimes(1));
-    expect(h.notify.mock.calls[0]![0]).toMatchObject({
-      message: "downloads.upload.addedConverting",
-    });
+    expect((h.notify.mock.calls[0]![0] as { message: NotifText }).message).toEqual(
+      msg("downloads.upload.addedConverting"),
+    );
     // Its finish is still to come, and the tray's to announce.
     expect(h.uploadEnded).toHaveBeenCalledWith(null);
   });